common, os, osd, test, tools: FileStore must work with ghobjects rather than hobjects

Add ghobject_t to hboject.h header
Add constants NO_SHARD/NO_GEN and change gen_t/shard_t
Convert other headers from hobject_t to ghobject_t
Mostly straight hobject_t to ghobject_t for src/os cc files
Fix tools and tests and enable ceph-dencoder
Add filename generation and parsing including unittest addition
Get ceph-filestore-dump to build
Add gen/shard to DBObjectMap::ghobject_key() and update test case
Add CEPH_FS_FEATURE_INCOMPAT_SHARDS new FileStore feature
Add CEPH_OSD_FEATURE_INCOMPAT_SHARDS new osd feature

Fixes: #5862

Signed-off-by: David Zafman <david.zafman@inktank.com>

31 files changed, 1090 insertions, 837 deletions

diff --git a/src/common/hobject.cc b/src/common/hobject.cc
index d6273693c62..b68baedd524 100644
--- a/src/common/hobject.cc
+++ b/src/common/hobject.cc
@@ -191,3 +191,90 @@ ostream& operator<<(ostream& out, const hobject_t& o)
   out << "/" << o.nspace << "/" << o.pool;
   return out;
 }
+
+// This is compatible with decode for hobject_t prior to
+// version 5.
+void ghobject_t::encode(bufferlist& bl) const
+{
+  ENCODE_START(5, 3, bl);
+  ::encode(hobj.key, bl);
+  ::encode(hobj.oid, bl);
+  ::encode(hobj.snap, bl);
+  ::encode(hobj.hash, bl);
+  ::encode(hobj.max, bl);
+  ::encode(hobj.nspace, bl);
+  ::encode(hobj.pool, bl);
+  ::encode(generation, bl);
+  ::encode(shard_id, bl);
+  ENCODE_FINISH(bl);
+}
+
+void ghobject_t::decode(bufferlist::iterator& bl)
+{
+  DECODE_START_LEGACY_COMPAT_LEN(5, 3, 3, bl);
+  if (struct_v >= 1)
+    ::decode(hobj.key, bl);
+  ::decode(hobj.oid, bl);
+  ::decode(hobj.snap, bl);
+  ::decode(hobj.hash, bl);
+  if (struct_v >= 2)
+    ::decode(hobj.max, bl);
+  else
+    hobj.max = false;
+  if (struct_v >= 4) {
+    ::decode(hobj.nspace, bl);
+    ::decode(hobj.pool, bl);
+  }
+  if (struct_v >= 5) {
+    ::decode(generation, bl);
+    ::decode(shard_id, bl);
+  } else {
+    generation = ghobject_t::NO_GEN;
+    shard_id = ghobject_t::NO_SHARD;
+  }
+  DECODE_FINISH(bl);
+}
+
+void ghobject_t::dump(Formatter *f) const
+{
+  hobj.dump(f);
+  if (generation != NO_GEN) {
+    f->dump_int("generation", generation);
+    f->dump_int("shard_id", shard_id);
+  }
+}
+
+void ghobject_t::generate_test_instances(list<ghobject_t*>& o)
+{
+  o.push_back(new ghobject_t);
+  o.push_back(new ghobject_t);
+  o.back()->hobj.max = true;
+  o.push_back(new ghobject_t(hobject_t(object_t("oname"), string(), 1, 234, -1, "")));
+
+  o.push_back(new ghobject_t(hobject_t(object_t("oname2"), string("okey"), CEPH_NOSNAP,
+	67, 0, "n1"), 1, 0));
+  o.push_back(new ghobject_t(hobject_t(object_t("oname2"), string("okey"), CEPH_NOSNAP,
+	67, 0, "n1"), 1, 1));
+  o.push_back(new ghobject_t(hobject_t(object_t("oname2"), string("okey"), CEPH_NOSNAP,
+	67, 0, "n1"), 1, 2));
+  o.push_back(new ghobject_t(hobject_t(object_t("oname3"), string("oname3"),
+	CEPH_SNAPDIR, 910, 1, "n2"), 1, 0));
+  o.push_back(new ghobject_t(hobject_t(object_t("oname3"), string("oname3"),
+	CEPH_SNAPDIR, 910, 1, "n2"), 2, 0));
+  o.push_back(new ghobject_t(hobject_t(object_t("oname3"), string("oname3"),
+	CEPH_SNAPDIR, 910, 1, "n2"), 3, 0));
+  o.push_back(new ghobject_t(hobject_t(object_t("oname3"), string("oname3"),
+	CEPH_SNAPDIR, 910, 1, "n2"), 3, 1));
+  o.push_back(new ghobject_t(hobject_t(object_t("oname3"), string("oname3"),
+	CEPH_SNAPDIR, 910, 1, "n2"), 3, 2));
+}
+
+ostream& operator<<(ostream& out, const ghobject_t& o)
+{
+  out << o.hobj;
+  if (o.generation != ghobject_t::NO_GEN) {
+    assert(o.shard_id != ghobject_t::NO_SHARD);
+    out << "/" << o.generation << "/" << o.shard_id;
+  }
+  return out;
+}
diff --git a/src/common/hobject.h b/src/common/hobject.h
index f455e9f780a..f8f58b4a245 100644
--- a/src/common/hobject.h
+++ b/src/common/hobject.h
@@ -153,6 +153,7 @@ public:
   friend bool operator>=(const hobject_t&, const hobject_t&);
   friend bool operator==(const hobject_t&, const hobject_t&);
   friend bool operator!=(const hobject_t&, const hobject_t&);
+  friend class ghobject_t;
 };
 WRITE_CLASS_ENCODER(hobject_t)
 
@@ -179,4 +180,98 @@ WRITE_CMP_OPERATORS_7(hobject_t,
 		      oid,
 		      snap)
 
+typedef uint64_t gen_t;
+typedef uint8_t shard_t;
+
+#ifndef UINT8_MAX
+#define UINT8_MAX (255)
+#endif
+#ifndef UINT64_MAX
+#define UINT64_MAX (18446744073709551615ULL)
+#endif
+
+struct ghobject_t {
+  hobject_t hobj;
+  gen_t generation;
+  shard_t shard_id;
+
+public:
+  static const shard_t NO_SHARD = UINT8_MAX;
+  static const gen_t NO_GEN = UINT64_MAX;
+
+  ghobject_t() : generation(NO_GEN), shard_id(NO_SHARD) {}
+
+  ghobject_t(const hobject_t &obj) : hobj(obj), generation(NO_GEN), shard_id(NO_SHARD) {}
+
+  ghobject_t(const hobject_t &obj, gen_t gen, shard_t shard) : hobj(obj), generation(gen), shard_id(shard) {}
+
+  bool match(uint32_t bits, uint32_t match) const {
+    return hobj.match_hash(hobj.hash, bits, match);
+  }
+  /// @return min ghobject_t ret s.t. ret.hash == this->hash
+  ghobject_t get_boundary() const {
+    if (hobj.is_max())
+      return *this;
+    ghobject_t ret;
+    ret.hobj.hash = hobj.hash;
+    return ret;
+  }
+  filestore_hobject_key_t get_filestore_key_u32() const {
+    assert(!hobj.max);
+    return hobj._reverse_nibbles(hobj.hash);
+  }
+  filestore_hobject_key_t get_filestore_key() const {
+    if (hobj.max)
+      return 0x100000000ull;
+    else
+      return get_filestore_key_u32();
+  }
+
+  // maximum sorted value.
+  static ghobject_t get_max() {
+    ghobject_t h(hobject_t::get_max());
+    return h;
+  }
+  bool is_max() const {
+    return hobj.is_max();
+  }
+
+  void swap(ghobject_t &o) {
+    ghobject_t temp(o);
+    o = (*this);
+    (*this) = temp;
+  }
+
+  void encode(bufferlist& bl) const;
+  void decode(bufferlist::iterator& bl);
+  void decode(json_spirit::Value& v);
+  void dump(Formatter *f) const;
+  static void generate_test_instances(list<ghobject_t*>& o);
+  friend bool operator<(const ghobject_t&, const ghobject_t&);
+  friend bool operator>(const ghobject_t&, const ghobject_t&);
+  friend bool operator<=(const ghobject_t&, const ghobject_t&);
+  friend bool operator>=(const ghobject_t&, const ghobject_t&);
+  friend bool operator==(const ghobject_t&, const ghobject_t&);
+  friend bool operator!=(const ghobject_t&, const ghobject_t&);
+};
+WRITE_CLASS_ENCODER(ghobject_t)
+
+namespace __gnu_cxx {
+  template<> struct hash<ghobject_t> {
+    size_t operator()(const ghobject_t &r) const {
+      static hash<object_t> H;
+      static rjhash<uint64_t> I;
+      return H(r.hobj.oid) ^ I(r.hobj.snap);
+    }
+  };
+}
+
+ostream& operator<<(ostream& out, const ghobject_t& o);
+
+WRITE_EQ_OPERATORS_3(ghobject_t, hobj, generation, shard_id)
+// sort ghobject_t's by <hobj, generation, shard_id>
+WRITE_CMP_OPERATORS_3(ghobject_t,
+		      hobj,
+		      shard_id,
+		      generation)
 #endif
diff --git a/src/os/CollectionIndex.h b/src/os/CollectionIndex.h
index 9afde11b187..89b7b862632 100644
--- a/src/os/CollectionIndex.h
+++ b/src/os/CollectionIndex.h
@@ -127,26 +127,26 @@ protected:
    * @return Error Code, 0 for success
    */
   virtual int created(
-    const hobject_t &hoid, ///< [in] Created object.
+    const ghobject_t &oid, ///< [in] Created object.
     const char *path       ///< [in] Path to created object.
     ) = 0;
 
   /**
-   * Removes hoid from the collection
+   * Removes oid from the collection
    *
    * @return Error Code, 0 for success
    */
   virtual int unlink(
-    const hobject_t &hoid ///< [in] Object to remove
+    const ghobject_t &oid ///< [in] Object to remove
     ) = 0;
 
   /**
-   * Gets the IndexedPath for hoid.
+   * Gets the IndexedPath for oid.
    *
    * @return Error Code, 0 for success
    */
   virtual int lookup(
-    const hobject_t &hoid, ///< [in] Object to lookup
+    const ghobject_t &oid, ///< [in] Object to lookup
     IndexedPath *path,	   ///< [out] Path to object
     int *exist	           ///< [out] True if the object exists, else false
     ) = 0;
@@ -167,17 +167,17 @@ protected:
 
   /// List contents of collection by hash
   virtual int collection_list_partial(
-    const hobject_t &start, ///< [in] object at which to start
+    const ghobject_t &start, ///< [in] object at which to start
     int min_count,          ///< [in] get at least min_count objects
     int max_count,          ///< [in] return at most max_count objects
     snapid_t seq,           ///< [in] list only objects with snap >= seq
-    vector<hobject_t> *ls,  ///< [out] Listed objects
-    hobject_t *next         ///< [out] Next object to list
+    vector<ghobject_t> *ls,  ///< [out] Listed objects
+    ghobject_t *next         ///< [out] Next object to list
     ) = 0;
 
   /// List contents of collection.
   virtual int collection_list(
-    vector<hobject_t> *ls ///< [out] Listed Objects
+    vector<ghobject_t> *ls ///< [out] Listed Objects
     ) = 0;
 
   /// Call prior to removing directory
diff --git a/src/os/DBObjectMap.cc b/src/os/DBObjectMap.cc
index 90c840bbe9c..635870b0db5 100644
--- a/src/os/DBObjectMap.cc
+++ b/src/os/DBObjectMap.cc
@@ -130,61 +130,68 @@ bool DBObjectMap::check(std::ostream &out)
   return retval;
 }
 
-string DBObjectMap::hobject_key(const hobject_t &hoid)
+string DBObjectMap::ghobject_key(const ghobject_t &oid)
 {
   string out;
-  append_escaped(hoid.oid.name, &out);
+  append_escaped(oid.hobj.oid.name, &out);
   out.push_back('.');
-  append_escaped(hoid.get_key(), &out);
+  append_escaped(oid.hobj.get_key(), &out);
   out.push_back('.');
-  append_escaped(hoid.nspace, &out);
+  append_escaped(oid.hobj.nspace, &out);
   out.push_back('.');
 
   char snap_with_hash[1000];
   char *t = snap_with_hash;
   char *end = t + sizeof(snap_with_hash);
-  if (hoid.snap == CEPH_NOSNAP)
+  if (oid.hobj.snap == CEPH_NOSNAP)
     t += snprintf(t, end - t, "head");
-  else if (hoid.snap == CEPH_SNAPDIR)
+  else if (oid.hobj.snap == CEPH_SNAPDIR)
     t += snprintf(t, end - t, "snapdir");
   else
-    t += snprintf(t, end - t, "%llx", (long long unsigned)hoid.snap);
+    t += snprintf(t, end - t, "%llx", (long long unsigned)oid.hobj.snap);
 
-  if (hoid.pool == -1)
+  if (oid.hobj.pool == -1)
     t += snprintf(t, end - t, ".none");
   else
-    t += snprintf(t, end - t, ".%llx", (long long unsigned)hoid.pool);
-  snprintf(t, end - t, ".%.*X", (int)(sizeof(hoid.hash)*2), hoid.hash);
+    t += snprintf(t, end - t, ".%llx", (long long unsigned)oid.hobj.pool);
+  snprintf(t, end - t, ".%.*X", (int)(sizeof(oid.hobj.hash)*2), oid.hobj.hash);
+
+  if (oid.generation != ghobject_t::NO_GEN) {
+    assert(oid.shard_id != ghobject_t::NO_SHARD);
+
+    t += snprintf(t, end - t, ".%llx", (long long unsigned)oid.generation);
+    t += snprintf(t, end - t, ".%x", (int)oid.shard_id);
+  }
   out += string(snap_with_hash);
   return out;
 }
 
-string DBObjectMap::hobject_key_v0(coll_t c, const hobject_t &hoid)
+string DBObjectMap::ghobject_key_v0(coll_t c, const ghobject_t &oid)
 {
   string out;
   append_escaped(c.to_str(), &out);
   out.push_back('.');
-  append_escaped(hoid.oid.name, &out);
+  append_escaped(oid.hobj.oid.name, &out);
   out.push_back('.');
-  append_escaped(hoid.get_key(), &out);
+  append_escaped(oid.hobj.get_key(), &out);
   out.push_back('.');
 
   char snap_with_hash[1000];
   char *t = snap_with_hash;
   char *end = t + sizeof(snap_with_hash);
-  if (hoid.snap == CEPH_NOSNAP)
+  if (oid.hobj.snap == CEPH_NOSNAP)
     t += snprintf(t, end - t, ".head");
-  else if (hoid.snap == CEPH_SNAPDIR)
+  else if (oid.hobj.snap == CEPH_SNAPDIR)
     t += snprintf(t, end - t, ".snapdir");
   else
-    t += snprintf(t, end - t, ".%llx", (long long unsigned)hoid.snap);
-  snprintf(t, end - t, ".%.*X", (int)(sizeof(hoid.hash)*2), hoid.hash);
+    t += snprintf(t, end - t, ".%llx", (long long unsigned)oid.hobj.snap);
+  snprintf(t, end - t, ".%.*X", (int)(sizeof(oid.hobj.hash)*2), oid.hobj.hash);
   out += string(snap_with_hash);
   return out;
 }
 
-bool DBObjectMap::parse_hobject_key_v0(const string &in, coll_t *c,
-				       hobject_t *hoid)
+bool DBObjectMap::parse_ghobject_key_v0(const string &in, coll_t *c,
+				       ghobject_t *oid)
 {
   string coll;
   string name;
@@ -244,13 +251,13 @@ bool DBObjectMap::parse_hobject_key_v0(const string &in, coll_t *c,
   pg_t pg;
   if (c->is_pg_prefix(pg))
     pool = (int64_t)pg.pool();
-  (*hoid) = hobject_t(name, key, snap, hash, pool, "");
+  (*oid) = ghobject_t(hobject_t(name, key, snap, hash, pool, ""));
   return true;
 }
 
-string DBObjectMap::map_header_key(const hobject_t &hoid)
+string DBObjectMap::map_header_key(const ghobject_t &oid)
 {
-  return hobject_key(hoid);
+  return ghobject_key(oid);
 }
 
 string DBObjectMap::header_key(uint64_t seq)
@@ -311,9 +318,9 @@ int DBObjectMap::DBObjectMapIteratorImpl::init()
 }
 
 ObjectMap::ObjectMapIterator DBObjectMap::get_iterator(
-  const hobject_t &hoid)
+  const ghobject_t &oid)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return ObjectMapIterator(new EmptyIteratorImpl());
   return _get_iterator(header);
@@ -496,15 +503,15 @@ int DBObjectMap::DBObjectMapIteratorImpl::status()
   return r;
 }
 
-int DBObjectMap::set_keys(const hobject_t &hoid,
+int DBObjectMap::set_keys(const ghobject_t &oid,
 			  const map<string, bufferlist> &set,
 			  const SequencerPosition *spos)
 {
   KeyValueDB::Transaction t = db->get_transaction();
-  Header header = lookup_create_map_header(hoid, t);
+  Header header = lookup_create_map_header(oid, t);
   if (!header)
     return -EINVAL;
-  if (check_spos(hoid, header, spos))
+  if (check_spos(oid, header, spos))
     return 0;
 
   t->set(user_prefix(header), set);
@@ -512,15 +519,15 @@ int DBObjectMap::set_keys(const hobject_t &hoid,
   return db->submit_transaction(t);
 }
 
-int DBObjectMap::set_header(const hobject_t &hoid,
+int DBObjectMap::set_header(const ghobject_t &oid,
 			    const bufferlist &bl,
 			    const SequencerPosition *spos)
 {
   KeyValueDB::Transaction t = db->get_transaction();
-  Header header = lookup_create_map_header(hoid, t);
+  Header header = lookup_create_map_header(oid, t);
   if (!header)
     return -EINVAL;
-  if (check_spos(hoid, header, spos))
+  if (check_spos(oid, header, spos))
     return 0;
   _set_header(header, bl, t);
   return db->submit_transaction(t);
@@ -534,10 +541,10 @@ void DBObjectMap::_set_header(Header header, const bufferlist &bl,
   t->set(sys_prefix(header), to_set);
 }
 
-int DBObjectMap::get_header(const hobject_t &hoid,
+int DBObjectMap::get_header(const ghobject_t &oid,
 			    bufferlist *bl)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header) {
     return 0;
   }
@@ -568,16 +575,16 @@ int DBObjectMap::_get_header(Header header,
   return 0;
 }
 
-int DBObjectMap::clear(const hobject_t &hoid,
+int DBObjectMap::clear(const ghobject_t &oid,
 		       const SequencerPosition *spos)
 {
   KeyValueDB::Transaction t = db->get_transaction();
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
-  if (check_spos(hoid, header, spos))
+  if (check_spos(oid, header, spos))
     return 0;
-  remove_map_header(hoid, header, t);
+  remove_map_header(oid, header, t);
   assert(header->num_children > 0);
   header->num_children--;
   int r = _clear(header, t);
@@ -688,15 +695,15 @@ int DBObjectMap::need_parent(DBObjectMapIterator iter)
   return 1;
 }
 
-int DBObjectMap::rm_keys(const hobject_t &hoid,
+int DBObjectMap::rm_keys(const ghobject_t &oid,
 			 const set<string> &to_clear,
 			 const SequencerPosition *spos)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
   KeyValueDB::Transaction t = db->get_transaction();
-  if (check_spos(hoid, header, spos))
+  if (check_spos(oid, header, spos))
     return 0;
   t->rmkeys(user_prefix(header), to_clear);
   if (!header->parent) {
@@ -756,17 +763,17 @@ int DBObjectMap::rm_keys(const hobject_t &hoid,
     parent->num_children--;
     _clear(parent, t);
     header->parent = 0;
-    set_map_header(hoid, *header, t);
+    set_map_header(oid, *header, t);
     t->rmkeys_by_prefix(complete_prefix(header));
   }
   return db->submit_transaction(t);
 }
 
-int DBObjectMap::get(const hobject_t &hoid,
+int DBObjectMap::get(const ghobject_t &oid,
 		     bufferlist *_header,
 		     map<string, bufferlist> *out)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
   _get_header(header, _header);
@@ -779,13 +786,13 @@ int DBObjectMap::get(const hobject_t &hoid,
   return 0;
 }
 
-int DBObjectMap::get_keys(const hobject_t &hoid,
+int DBObjectMap::get_keys(const ghobject_t &oid,
 			  set<string> *keys)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
-  ObjectMapIterator iter = get_iterator(hoid);
+  ObjectMapIterator iter = get_iterator(oid);
   for (; iter->valid(); iter->next()) {
     if (iter->status())
       return iter->status();
@@ -816,40 +823,40 @@ int DBObjectMap::scan(Header header,
   return 0;
 }
 
-int DBObjectMap::get_values(const hobject_t &hoid,
+int DBObjectMap::get_values(const ghobject_t &oid,
 			    const set<string> &keys,
 			    map<string, bufferlist> *out)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
   return scan(header, keys, 0, out);
 }
 
-int DBObjectMap::check_keys(const hobject_t &hoid,
+int DBObjectMap::check_keys(const ghobject_t &oid,
 			    const set<string> &keys,
 			    set<string> *out)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
   return scan(header, keys, out, 0);
 }
 
-int DBObjectMap::get_xattrs(const hobject_t &hoid,
+int DBObjectMap::get_xattrs(const ghobject_t &oid,
 			    const set<string> &to_get,
 			    map<string, bufferlist> *out)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
   return db->get(xattr_prefix(header), to_get, out);
 }
 
-int DBObjectMap::get_all_xattrs(const hobject_t &hoid,
+int DBObjectMap::get_all_xattrs(const ghobject_t &oid,
 				set<string> *out)
 {
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
   KeyValueDB::Iterator iter = db->get_iterator(xattr_prefix(header));
@@ -860,39 +867,39 @@ int DBObjectMap::get_all_xattrs(const hobject_t &hoid,
   return iter->status();
 }
 
-int DBObjectMap::set_xattrs(const hobject_t &hoid,
+int DBObjectMap::set_xattrs(const ghobject_t &oid,
 			    const map<string, bufferlist> &to_set,
 			    const SequencerPosition *spos)
 {
   KeyValueDB::Transaction t = db->get_transaction();
-  Header header = lookup_create_map_header(hoid, t);
+  Header header = lookup_create_map_header(oid, t);
   if (!header)
     return -EINVAL;
-  if (check_spos(hoid, header, spos))
+  if (check_spos(oid, header, spos))
     return 0;
   t->set(xattr_prefix(header), to_set);
   return db->submit_transaction(t);
 }
 
-int DBObjectMap::remove_xattrs(const hobject_t &hoid,
+int DBObjectMap::remove_xattrs(const ghobject_t &oid,
 			       const set<string> &to_remove,
 			       const SequencerPosition *spos)
 {
   KeyValueDB::Transaction t = db->get_transaction();
-  Header header = lookup_map_header(hoid);
+  Header header = lookup_map_header(oid);
   if (!header)
     return -ENOENT;
-  if (check_spos(hoid, header, spos))
+  if (check_spos(oid, header, spos))
     return 0;
   t->rmkeys(xattr_prefix(header), to_remove);
   return db->submit_transaction(t);
 }
 
-int DBObjectMap::clone(const hobject_t &hoid,
-		       const hobject_t &target,
+int DBObjectMap::clone(const ghobject_t &oid,
+		       const ghobject_t &target,
 		       const SequencerPosition *spos)
 {
-  if (hoid == target)
+  if (oid == target)
     return 0;
 
   KeyValueDB::Transaction t = db->get_transaction();
@@ -907,18 +914,18 @@ int DBObjectMap::clone(const hobject_t &hoid,
     }
   }
 
-  Header parent = lookup_map_header(hoid);
+  Header parent = lookup_map_header(oid);
   if (!parent)
     return db->submit_transaction(t);
 
-  Header source = generate_new_header(hoid, parent);
+  Header source = generate_new_header(oid, parent);
   Header destination = generate_new_header(target, parent);
   if (spos)
     destination->spos = *spos;
 
   parent->num_children = 2;
   set_header(parent, t);
-  set_map_header(hoid, *source, t);
+  set_map_header(oid, *source, t);
   set_map_header(target, *destination, t);
 
   map<string, bufferlist> to_set;
@@ -973,9 +980,9 @@ int DBObjectMap::upgrade()
 		 to_get);
 
       coll_t coll;
-      hobject_t hoid;
-      assert(parse_hobject_key_v0(iter->key(), &coll, &hoid));
-      new_map_headers[hobject_key(hoid)] = got.begin()->second;
+      ghobject_t oid;
+      assert(parse_ghobject_key_v0(iter->key(), &coll, &oid));
+      new_map_headers[ghobject_key(oid)] = got.begin()->second;
     }
 
     t->rmkeys(LEAF_PREFIX, legacy_to_remove);
@@ -1038,18 +1045,18 @@ int DBObjectMap::init(bool do_upgrade)
   return 0;
 }
 
-int DBObjectMap::sync(const hobject_t *hoid,
+int DBObjectMap::sync(const ghobject_t *oid,
 		      const SequencerPosition *spos) {
   KeyValueDB::Transaction t = db->get_transaction();
   write_state(t);
-  if (hoid) {
+  if (oid) {
     assert(spos);
-    Header header = lookup_map_header(*hoid);
+    Header header = lookup_map_header(*oid);
     if (header) {
-      dout(10) << "hoid: " << *hoid << " setting spos to "
+      dout(10) << "oid: " << *oid << " setting spos to "
 	       << *spos << dendl;
       header->spos = *spos;
-      set_map_header(*hoid, *header, t);
+      set_map_header(*oid, *header, t);
     }
   }
   return db->submit_transaction_sync(t);
@@ -1067,27 +1074,27 @@ int DBObjectMap::write_state(KeyValueDB::Transaction _t) {
 }
 
 
-DBObjectMap::Header DBObjectMap::_lookup_map_header(const hobject_t &hoid)
+DBObjectMap::Header DBObjectMap::_lookup_map_header(const ghobject_t &oid)
 {
-  while (map_header_in_use.count(hoid))
+  while (map_header_in_use.count(oid))
     header_cond.Wait(header_lock);
 
   map<string, bufferlist> out;
   set<string> to_get;
-  to_get.insert(map_header_key(hoid));
+  to_get.insert(map_header_key(oid));
   int r = db->get(HOBJECT_TO_SEQ, to_get, &out);
   if (r < 0)
     return Header();
   if (out.empty())
     return Header();
   
-  Header ret(new _Header(), RemoveMapHeaderOnDelete(this, hoid));
+  Header ret(new _Header(), RemoveMapHeaderOnDelete(this, oid));
   bufferlist::iterator iter = out.begin()->second.begin();
   ret->decode(iter);
   return ret;
 }
 
-DBObjectMap::Header DBObjectMap::_generate_new_header(const hobject_t &hoid,
+DBObjectMap::Header DBObjectMap::_generate_new_header(const ghobject_t &oid,
 						      Header parent)
 {
   Header header = Header(new _Header(), RemoveOnDelete(this));
@@ -1097,7 +1104,7 @@ DBObjectMap::Header DBObjectMap::_generate_new_header(const hobject_t &hoid,
     header->spos = parent->spos;
   }
   header->num_children = 1;
-  header->hoid = hoid;
+  header->oid = oid;
   assert(!in_use.count(header->seq));
   in_use.insert(header->seq);
 
@@ -1137,14 +1144,14 @@ DBObjectMap::Header DBObjectMap::lookup_parent(Header input)
 }
 
 DBObjectMap::Header DBObjectMap::lookup_create_map_header(
-  const hobject_t &hoid,
+  const ghobject_t &oid,
   KeyValueDB::Transaction t)
 {
   Mutex::Locker l(header_lock);
-  Header header = _lookup_map_header(hoid);
+  Header header = _lookup_map_header(oid);
   if (!header) {
-    header = _generate_new_header(hoid, Header());
-    set_map_header(hoid, *header, t);
+    header = _generate_new_header(oid, Header());
+    set_map_header(oid, *header, t);
   }
   return header;
 }
@@ -1169,50 +1176,50 @@ void DBObjectMap::set_header(Header header, KeyValueDB::Transaction t)
   t->set(sys_prefix(header), to_write);
 }
 
-void DBObjectMap::remove_map_header(const hobject_t &hoid,
+void DBObjectMap::remove_map_header(const ghobject_t &oid,
 				    Header header,
 				    KeyValueDB::Transaction t)
 {
   dout(20) << "remove_map_header: removing " << header->seq
-	   << " hoid " << hoid << dendl;
+	   << " oid " << oid << dendl;
   set<string> to_remove;
-  to_remove.insert(map_header_key(hoid));
+  to_remove.insert(map_header_key(oid));
   t->rmkeys(HOBJECT_TO_SEQ, to_remove);
 }
 
-void DBObjectMap::set_map_header(const hobject_t &hoid, _Header header,
+void DBObjectMap::set_map_header(const ghobject_t &oid, _Header header,
 				 KeyValueDB::Transaction t)
 {
   dout(20) << "set_map_header: setting " << header.seq
-	   << " hoid " << hoid << " parent seq "
+	   << " oid " << oid << " parent seq "
 	   << header.parent << dendl;
   map<string, bufferlist> to_set;
-  header.encode(to_set[map_header_key(hoid)]);
+  header.encode(to_set[map_header_key(oid)]);
   t->set(HOBJECT_TO_SEQ, to_set);
 }
 
-bool DBObjectMap::check_spos(const hobject_t &hoid,
+bool DBObjectMap::check_spos(const ghobject_t &oid,
 			     Header header,
 			     const SequencerPosition *spos)
 {
   if (!spos || *spos > header->spos) {
     stringstream out;
     if (spos)
-      dout(10) << "hoid: " << hoid << " not skipping op, *spos "
+      dout(10) << "oid: " << oid << " not skipping op, *spos "
 	       << *spos << dendl;
     else
-      dout(10) << "hoid: " << hoid << " not skipping op, *spos "
+      dout(10) << "oid: " << oid << " not skipping op, *spos "
 	       << "empty" << dendl;
     dout(10) << " > header.spos " << header->spos << dendl;
     return false;
   } else {
-    dout(10) << "hoid: " << hoid << " skipping op, *spos " << *spos
+    dout(10) << "oid: " << oid << " skipping op, *spos " << *spos
 	     << " <= header.spos " << header->spos << dendl;
     return true;
   }
 }
 
-int DBObjectMap::list_objects(vector<hobject_t> *out)
+int DBObjectMap::list_objects(vector<ghobject_t> *out)
 {
   KeyValueDB::Iterator iter = db->get_iterator(HOBJECT_TO_SEQ);
   for (iter->seek_to_first(); iter->valid(); iter->next()) {
@@ -1220,7 +1227,7 @@ int DBObjectMap::list_objects(vector<hobject_t> *out)
     bufferlist::iterator bliter = bl.begin();
     _Header header;
     header.decode(bliter);
-    out->push_back(header.hoid);
+    out->push_back(header.oid);
   }
   return 0;
 }
diff --git a/src/os/DBObjectMap.h b/src/os/DBObjectMap.h
index ba05dff6c6f..459447f9c97 100644
--- a/src/os/DBObjectMap.h
+++ b/src/os/DBObjectMap.h
@@ -26,7 +26,7 @@
  * @see user_prefix
  * @see sys_prefix
  *
- * - HOBJECT_TO_SEQ: Contains leaf mapping from hobject_t->seq and
+ * - GHOBJECT_TO_SEQ: Contains leaf mapping from ghobject_t->hobj.seq and
  *                   corresponding omap header
  * - SYS_PREFIX: GLOBAL_STATE_KEY - contains next seq number
  *                                  @see State
@@ -66,89 +66,89 @@ public:
    * Set of headers currently in use
    */
   set<uint64_t> in_use;
-  set<hobject_t> map_header_in_use;
+  set<ghobject_t> map_header_in_use;
 
   DBObjectMap(KeyValueDB *db) : db(db),
 				header_lock("DBOBjectMap")
     {}
 
   int set_keys(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const map<string, bufferlist> &set,
     const SequencerPosition *spos=0
     );
 
   int set_header(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const bufferlist &bl,
     const SequencerPosition *spos=0
     );
 
   int get_header(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     bufferlist *bl
     );
 
   int clear(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const SequencerPosition *spos=0
     );
 
   int rm_keys(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const set<string> &to_clear,
     const SequencerPosition *spos=0
     );
 
   int get(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     bufferlist *header,
     map<string, bufferlist> *out
     );
 
   int get_keys(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     set<string> *keys
     );
 
   int get_values(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const set<string> &keys,
     map<string, bufferlist> *out
     );
 
   int check_keys(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const set<string> &keys,
     set<string> *out
     );
 
   int get_xattrs(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const set<string> &to_get,
     map<string, bufferlist> *out
     );
 
   int get_all_xattrs(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     set<string> *out
     );
 
   int set_xattrs(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const map<string, bufferlist> &to_set,
     const SequencerPosition *spos=0
     );
 
   int remove_xattrs(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const set<string> &to_remove,
     const SequencerPosition *spos=0
     );
 
   int clone(
-    const hobject_t &hoid,
-    const hobject_t &target,
+    const ghobject_t &oid,
+    const ghobject_t &target,
     const SequencerPosition *spos=0
     );
 
@@ -162,13 +162,13 @@ public:
   bool check(std::ostream &out);
 
   /// Ensure that all previous operations are durable
-  int sync(const hobject_t *hoid=0, const SequencerPosition *spos=0);
+  int sync(const ghobject_t *oid=0, const SequencerPosition *spos=0);
 
   /// Util, list all objects, there must be no other concurrent access
-  int list_objects(vector<hobject_t> *objs ///< [out] objects
+  int list_objects(vector<ghobject_t> *objs ///< [out] objects
     );
 
-  ObjectMapIterator get_iterator(const hobject_t &hoid);
+  ObjectMapIterator get_iterator(const ghobject_t &oid);
 
   static const string USER_PREFIX;
   static const string XATTR_PREFIX;
@@ -223,7 +223,7 @@ public:
     uint64_t num_children;
 
     coll_t c;
-    hobject_t hoid;
+    ghobject_t oid;
 
     SequencerPosition spos;
 
@@ -233,7 +233,7 @@ public:
       ::encode(parent, bl);
       ::encode(num_children, bl);
       ::encode(c, bl);
-      ::encode(hoid, bl);
+      ::encode(oid, bl);
       ::encode(spos, bl);
       ENCODE_FINISH(bl);
     }
@@ -244,7 +244,7 @@ public:
       ::decode(parent, bl);
       ::decode(num_children, bl);
       ::decode(c, bl);
-      ::decode(hoid, bl);
+      ::decode(oid, bl);
       if (struct_v >= 2)
 	::decode(spos, bl);
       DECODE_FINISH(bl);
@@ -255,7 +255,7 @@ public:
       f->dump_unsigned("parent", parent);
       f->dump_unsigned("num_children", num_children);
       f->dump_stream("coll") << c;
-      f->dump_stream("oid") << hoid;
+      f->dump_stream("oid") << oid;
     }
 
     static void generate_test_instances(list<_Header*> &o) {
@@ -269,15 +269,15 @@ public:
   };
 
   /// String munging (public for testing)
-  static string hobject_key(const hobject_t &hoid);
-  static string hobject_key_v0(coll_t c, const hobject_t &hoid);
-  static bool parse_hobject_key_v0(const string &in,
-				   coll_t *c, hobject_t *hoid);
+  static string ghobject_key(const ghobject_t &oid);
+  static string ghobject_key_v0(coll_t c, const ghobject_t &oid);
+  static bool parse_ghobject_key_v0(const string &in,
+				   coll_t *c, ghobject_t *oid);
 private:
   /// Implicit lock on Header->seq
   typedef std::tr1::shared_ptr<_Header> Header;
 
-  string map_header_key(const hobject_t &hoid);
+  string map_header_key(const ghobject_t &oid);
   string header_key(uint64_t seq);
   string complete_prefix(Header header);
   string user_prefix(Header header);
@@ -368,40 +368,40 @@ private:
   /// Set node containing input to new contents
   void set_header(Header input, KeyValueDB::Transaction t);
 
-  /// Remove leaf node corresponding to hoid in c
-  void remove_map_header(const hobject_t &hoid,
+  /// Remove leaf node corresponding to oid in c
+  void remove_map_header(const ghobject_t &oid,
 			 Header header,
 			 KeyValueDB::Transaction t);
 
-  /// Set leaf node for c and hoid to the value of header
-  void set_map_header(const hobject_t &hoid, _Header header,
+  /// Set leaf node for c and oid to the value of header
+  void set_map_header(const ghobject_t &oid, _Header header,
 		      KeyValueDB::Transaction t);
 
-  /// Set leaf node for c and hoid to the value of header
-  bool check_spos(const hobject_t &hoid,
+  /// Set leaf node for c and oid to the value of header
+  bool check_spos(const ghobject_t &oid,
 		  Header header,
 		  const SequencerPosition *spos);
 
-  /// Lookup or create header for c hoid
-  Header lookup_create_map_header(const hobject_t &hoid,
+  /// Lookup or create header for c oid
+  Header lookup_create_map_header(const ghobject_t &oid,
 				  KeyValueDB::Transaction t);
 
   /**
-   * Generate new header for c hoid with new seq number
+   * Generate new header for c oid with new seq number
    *
    * Has the side effect of syncronously saving the new DBObjectMap state
    */
-  Header _generate_new_header(const hobject_t &hoid, Header parent);
-  Header generate_new_header(const hobject_t &hoid, Header parent) {
+  Header _generate_new_header(const ghobject_t &oid, Header parent);
+  Header generate_new_header(const ghobject_t &oid, Header parent) {
     Mutex::Locker l(header_lock);
-    return _generate_new_header(hoid, parent);
+    return _generate_new_header(oid, parent);
   }
 
-  /// Lookup leaf header for c hoid
-  Header _lookup_map_header(const hobject_t &hoid);
-  Header lookup_map_header(const hobject_t &hoid) {
+  /// Lookup leaf header for c oid
+  Header _lookup_map_header(const ghobject_t &oid);
+  Header lookup_map_header(const ghobject_t &oid) {
     Mutex::Locker l(header_lock);
-    return _lookup_map_header(hoid);
+    return _lookup_map_header(oid);
   }
 
   /// Lookup header node for input
@@ -448,12 +448,12 @@ private:
   class RemoveMapHeaderOnDelete {
   public:
     DBObjectMap *db;
-    hobject_t obj;
-    RemoveMapHeaderOnDelete(DBObjectMap *db, const hobject_t &obj) :
-      db(db), obj(obj) {}
+    ghobject_t oid;
+    RemoveMapHeaderOnDelete(DBObjectMap *db, const ghobject_t &oid) :
+      db(db), oid(oid) {}
     void operator() (_Header *header) {
       Mutex::Locker l(db->header_lock);
-      db->map_header_in_use.erase(obj);
+      db->map_header_in_use.erase(oid);
       db->map_header_cond.Signal();
       delete header;
     }
diff --git a/src/os/FDCache.h b/src/os/FDCache.h
index 00e632f3e0f..93557d43c47 100644
--- a/src/os/FDCache.h
+++ b/src/os/FDCache.h
@@ -49,7 +49,7 @@ public:
   };
 
 private:
-  SharedLRU<hobject_t, FD> registry;
+  SharedLRU<ghobject_t, FD> registry;
   CephContext *cct;
 
 public:
@@ -63,16 +63,16 @@ public:
   }
   typedef std::tr1::shared_ptr<FD> FDRef;
 
-  FDRef lookup(const hobject_t &hoid) {
+  FDRef lookup(const ghobject_t &hoid) {
     return registry.lookup(hoid);
   }
 
-  FDRef add(const hobject_t &hoid, int fd) {
+  FDRef add(const ghobject_t &hoid, int fd) {
     return registry.add(hoid, new FD(fd));
   }
 
   /// clear cached fd for hoid, subsequent lookups will get an empty FD
-  void clear(const hobject_t &hoid) {
+  void clear(const ghobject_t &hoid) {
     registry.clear(hoid);
     assert(!registry.lookup(hoid));
   }
diff --git a/src/os/FileStore.cc b/src/os/FileStore.cc
index 6a79d54673f..6e1e4688996 100644
--- a/src/os/FileStore.cc
+++ b/src/os/FileStore.cc
@@ -145,7 +145,7 @@ int FileStore::init_index(coll_t cid)
   return r;
 }
 
-int FileStore::lfn_find(coll_t cid, const hobject_t& oid, IndexedPath *path)
+int FileStore::lfn_find(coll_t cid, const ghobject_t& oid, IndexedPath *path)
 {
   Index index; 
   int r, exist;
@@ -163,7 +163,7 @@ int FileStore::lfn_find(coll_t cid, const hobject_t& oid, IndexedPath *path)
   return 0;
 }
 
-int FileStore::lfn_truncate(coll_t cid, const hobject_t& oid, off_t length)
+int FileStore::lfn_truncate(coll_t cid, const ghobject_t& oid, off_t length)
 {
   IndexedPath path;
   int r = lfn_find(cid, oid, &path);
@@ -176,7 +176,7 @@ int FileStore::lfn_truncate(coll_t cid, const hobject_t& oid, off_t length)
   return r;
 }
 
-int FileStore::lfn_stat(coll_t cid, const hobject_t& oid, struct stat *buf)
+int FileStore::lfn_stat(coll_t cid, const ghobject_t& oid, struct stat *buf)
 {
   IndexedPath path;
   int r = lfn_find(cid, oid, &path);
@@ -189,12 +189,13 @@ int FileStore::lfn_stat(coll_t cid, const hobject_t& oid, struct stat *buf)
 }
 
 int FileStore::lfn_open(coll_t cid,
-			const hobject_t& oid,
+			const ghobject_t& oid,
 			bool create,
 			FDRef *outfd,
 			IndexedPath *path,
 			Index *index) 
 {
+  assert(get_allow_sharded_objects() || oid.shard_id == ghobject_t::NO_SHARD);
   assert(outfd);
   int flags = O_RDWR;
   if (create)
@@ -262,7 +263,7 @@ void FileStore::lfn_close(FDRef fd)
 {
 }
 
-int FileStore::lfn_link(coll_t c, coll_t newcid, const hobject_t& o, const hobject_t& newoid)
+int FileStore::lfn_link(coll_t c, coll_t newcid, const ghobject_t& o, const ghobject_t& newoid)
 {
   Index index_new, index_old;
   IndexedPath path_new, path_old;
@@ -314,7 +315,7 @@ int FileStore::lfn_link(coll_t c, coll_t newcid, const hobject_t& o, const hobje
   return 0;
 }
 
-int FileStore::lfn_unlink(coll_t cid, const hobject_t& o,
+int FileStore::lfn_unlink(coll_t cid, const ghobject_t& o,
 			  const SequencerPosition &spos,
 			  bool force_clear_omap)
 {
@@ -1912,7 +1913,7 @@ void FileStore::_set_replay_guard(coll_t cid,
 
 void FileStore::_set_replay_guard(int fd,
 				  const SequencerPosition& spos,
-				  const hobject_t *hoid,
+				  const ghobject_t *hoid,
 				  bool in_progress)
 {
   if (backend->can_checkpoint())
@@ -1993,7 +1994,7 @@ void FileStore::_close_replay_guard(int fd, const SequencerPosition& spos)
   dout(10) << "_close_replay_guard " << spos << " done" << dendl;
 }
 
-int FileStore::_check_replay_guard(coll_t cid, hobject_t oid, const SequencerPosition& spos)
+int FileStore::_check_replay_guard(coll_t cid, ghobject_t oid, const SequencerPosition& spos)
 {
   if (!replaying || backend->can_checkpoint())
     return 1;
@@ -2091,7 +2092,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_TOUCH:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	if (_check_replay_guard(cid, oid, spos) > 0)
 	  r = _touch(cid, oid);
       }
@@ -2100,7 +2101,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_WRITE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	uint64_t off = i.get_length();
 	uint64_t len = i.get_length();
 	bool replica = i.get_replica();
@@ -2114,7 +2115,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_ZERO:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	uint64_t off = i.get_length();
 	uint64_t len = i.get_length();
 	if (_check_replay_guard(cid, oid, spos) > 0)
@@ -2135,7 +2136,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_TRUNCATE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	uint64_t off = i.get_length();
 	if (_check_replay_guard(cid, oid, spos) > 0)
 	  r = _truncate(cid, oid, off);
@@ -2145,7 +2146,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_REMOVE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	if (_check_replay_guard(cid, oid, spos) > 0)
 	  r = _remove(cid, oid, spos);
       }
@@ -2154,7 +2155,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_SETATTR:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	string name = i.get_attrname();
 	bufferlist bl;
 	i.get_bl(bl);
@@ -2172,7 +2173,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_SETATTRS:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	map<string, bufferptr> aset;
 	i.get_attrset(aset);
 	if (_check_replay_guard(cid, oid, spos) > 0)
@@ -2185,7 +2186,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_RMATTR:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	string name = i.get_attrname();
 	if (_check_replay_guard(cid, oid, spos) > 0)
 	  r = _rmattr(cid, oid, name.c_str(), spos);
@@ -2195,7 +2196,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_RMATTRS:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	if (_check_replay_guard(cid, oid, spos) > 0)
 	  r = _rmattrs(cid, oid, spos);
       }
@@ -2204,8 +2205,8 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_CLONE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
-	hobject_t noid = i.get_oid();
+	ghobject_t oid = i.get_oid();
+	ghobject_t noid = i.get_oid();
 	r = _clone(cid, oid, noid, spos);
       }
       break;
@@ -2213,8 +2214,8 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_CLONERANGE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
-	hobject_t noid = i.get_oid();
+	ghobject_t oid = i.get_oid();
+	ghobject_t noid = i.get_oid();
  	uint64_t off = i.get_length();
 	uint64_t len = i.get_length();
 	r = _clone_range(cid, oid, noid, off, len, off, spos);
@@ -2224,8 +2225,8 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_CLONERANGE2:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
-	hobject_t noid = i.get_oid();
+	ghobject_t oid = i.get_oid();
+	ghobject_t noid = i.get_oid();
  	uint64_t srcoff = i.get_length();
 	uint64_t len = i.get_length();
  	uint64_t dstoff = i.get_length();
@@ -2253,7 +2254,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
       {
 	coll_t ncid = i.get_cid();
 	coll_t ocid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	r = _collection_add(ncid, ocid, oid, spos);
       }
       break;
@@ -2261,7 +2262,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_COLL_REMOVE:
        {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	if (_check_replay_guard(cid, oid, spos) > 0)
 	  r = _remove(cid, oid, spos);
        }
@@ -2272,7 +2273,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
 	// WARNING: this is deprecated and buggy; only here to replay old journals.
 	coll_t ocid = i.get_cid();
 	coll_t ncid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	r = _collection_add(ocid, ncid, oid, spos);
 	if (r == 0 &&
 	    (_check_replay_guard(ocid, oid, spos) > 0))
@@ -2283,9 +2284,9 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_COLL_MOVE_RENAME:
       {
 	coll_t oldcid = i.get_cid();
-	hobject_t oldoid = i.get_oid();
+	ghobject_t oldoid = i.get_oid();
 	coll_t newcid = i.get_cid();
-	hobject_t newoid = i.get_oid();
+	ghobject_t newoid = i.get_oid();
 	r = _collection_move_rename(oldcid, oldoid, newcid, newoid, spos);
       }
       break;
@@ -2325,14 +2326,14 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_OMAP_CLEAR:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	r = _omap_clear(cid, oid, spos);
       }
       break;
     case Transaction::OP_OMAP_SETKEYS:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	map<string, bufferlist> aset;
 	i.get_attrset(aset);
 	r = _omap_setkeys(cid, oid, aset, spos);
@@ -2341,7 +2342,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_OMAP_RMKEYS:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	set<string> keys;
 	i.get_keyset(keys);
 	r = _omap_rmkeys(cid, oid, keys, spos);
@@ -2350,7 +2351,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_OMAP_RMKEYRANGE:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	string first, last;
 	first = i.get_key();
 	last = i.get_key();
@@ -2360,7 +2361,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
     case Transaction::OP_OMAP_SETHEADER:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	bufferlist bl;
 	i.get_bl(bl);
 	r = _omap_setheader(cid, oid, bl, spos);
@@ -2480,7 +2481,7 @@ unsigned FileStore::_do_transaction(Transaction& t, uint64_t op_seq, int trans_n
 // --------------------
 // objects
 
-bool FileStore::exists(coll_t cid, const hobject_t& oid)
+bool FileStore::exists(coll_t cid, const ghobject_t& oid)
 {
   struct stat st;
   if (stat(cid, oid, &st) == 0)
@@ -2490,7 +2491,7 @@ bool FileStore::exists(coll_t cid, const hobject_t& oid)
 }
   
 int FileStore::stat(
-  coll_t cid, const hobject_t& oid, struct stat *st, bool allow_eio)
+  coll_t cid, const ghobject_t& oid, struct stat *st, bool allow_eio)
 {
   int r = lfn_stat(cid, oid, st);
   assert(allow_eio || !m_filestore_fail_eio || r != -EIO);
@@ -2512,7 +2513,7 @@ int FileStore::stat(
 
 int FileStore::read(
   coll_t cid,
-  const hobject_t& oid, 
+  const ghobject_t& oid,
   uint64_t offset,
   size_t len,
   bufferlist& bl,
@@ -2560,7 +2561,7 @@ int FileStore::read(
   }
 }
 
-int FileStore::fiemap(coll_t cid, const hobject_t& oid,
+int FileStore::fiemap(coll_t cid, const ghobject_t& oid,
                     uint64_t offset, size_t len,
                     bufferlist& bl)
 {
@@ -2638,7 +2639,7 @@ done:
 }
 
 
-int FileStore::_remove(coll_t cid, const hobject_t& oid,
+int FileStore::_remove(coll_t cid, const ghobject_t& oid,
 		       const SequencerPosition &spos) 
 {
   dout(15) << "remove " << cid << "/" << oid << dendl;
@@ -2647,7 +2648,7 @@ int FileStore::_remove(coll_t cid, const hobject_t& oid,
   return r;
 }
 
-int FileStore::_truncate(coll_t cid, const hobject_t& oid, uint64_t size)
+int FileStore::_truncate(coll_t cid, const ghobject_t& oid, uint64_t size)
 {
   dout(15) << "truncate " << cid << "/" << oid << " size " << size << dendl;
   int r = lfn_truncate(cid, oid, size);
@@ -2656,7 +2657,7 @@ int FileStore::_truncate(coll_t cid, const hobject_t& oid, uint64_t size)
 }
 
 
-int FileStore::_touch(coll_t cid, const hobject_t& oid)
+int FileStore::_touch(coll_t cid, const ghobject_t& oid)
 {
   dout(15) << "touch " << cid << "/" << oid << dendl;
 
@@ -2671,7 +2672,7 @@ int FileStore::_touch(coll_t cid, const hobject_t& oid)
   return r;
 }
 
-int FileStore::_write(coll_t cid, const hobject_t& oid, 
+int FileStore::_write(coll_t cid, const ghobject_t& oid,
                      uint64_t offset, size_t len,
                      const bufferlist& bl, bool replica)
 {
@@ -2720,7 +2721,7 @@ int FileStore::_write(coll_t cid, const hobject_t& oid,
   return r;
 }
 
-int FileStore::_zero(coll_t cid, const hobject_t& oid, uint64_t offset, size_t len)
+int FileStore::_zero(coll_t cid, const ghobject_t& oid, uint64_t offset, size_t len)
 {
   dout(15) << "zero " << cid << "/" << oid << " " << offset << "~" << len << dendl;
   int ret = 0;
@@ -2763,7 +2764,7 @@ int FileStore::_zero(coll_t cid, const hobject_t& oid, uint64_t offset, size_t l
   return ret;
 }
 
-int FileStore::_clone(coll_t cid, const hobject_t& oldoid, const hobject_t& newoid,
+int FileStore::_clone(coll_t cid, const ghobject_t& oldoid, const ghobject_t& newoid,
 		      const SequencerPosition& spos)
 {
   dout(15) << "clone " << cid << "/" << oldoid << " -> " << cid << "/" << newoid << dendl;
@@ -2897,7 +2898,7 @@ int FileStore::_do_copy_range(int from, int to, uint64_t srcoff, uint64_t len, u
   return r;
 }
 
-int FileStore::_clone_range(coll_t cid, const hobject_t& oldoid, const hobject_t& newoid,
+int FileStore::_clone_range(coll_t cid, const ghobject_t& oldoid, const ghobject_t& newoid,
 			    uint64_t srcoff, uint64_t len, uint64_t dstoff,
 			    const SequencerPosition& spos)
 {
@@ -3338,23 +3339,23 @@ int FileStore::_fsetattrs(int fd, map<string, bufferptr> &aset)
 }
 
 // debug EIO injection
-void FileStore::inject_data_error(const hobject_t &oid) {
+void FileStore::inject_data_error(const ghobject_t &oid) {
   Mutex::Locker l(read_error_lock);
   dout(10) << __func__ << ": init error on " << oid << dendl;
   data_error_set.insert(oid);
 }
-void FileStore::inject_mdata_error(const hobject_t &oid) {
+void FileStore::inject_mdata_error(const ghobject_t &oid) {
   Mutex::Locker l(read_error_lock);
   dout(10) << __func__ << ": init error on " << oid << dendl;
   mdata_error_set.insert(oid);
 }
-void FileStore::debug_obj_on_delete(const hobject_t &oid) {
+void FileStore::debug_obj_on_delete(const ghobject_t &oid) {
   Mutex::Locker l(read_error_lock);
   dout(10) << __func__ << ": clear error on " << oid << dendl;
   data_error_set.erase(oid);
   mdata_error_set.erase(oid);
 }
-bool FileStore::debug_data_eio(const hobject_t &oid) {
+bool FileStore::debug_data_eio(const ghobject_t &oid) {
   Mutex::Locker l(read_error_lock);
   if (data_error_set.count(oid)) {
     dout(10) << __func__ << ": inject error on " << oid << dendl;
@@ -3363,7 +3364,7 @@ bool FileStore::debug_data_eio(const hobject_t &oid) {
     return false;
   }
 }
-bool FileStore::debug_mdata_eio(const hobject_t &oid) {
+bool FileStore::debug_mdata_eio(const ghobject_t &oid) {
   Mutex::Locker l(read_error_lock);
   if (mdata_error_set.count(oid)) {
     dout(10) << __func__ << ": inject error on " << oid << dendl;
@@ -3376,7 +3377,7 @@ bool FileStore::debug_mdata_eio(const hobject_t &oid) {
 
 // objects
 
-int FileStore::getattr(coll_t cid, const hobject_t& oid, const char *name, bufferptr &bp)
+int FileStore::getattr(coll_t cid, const ghobject_t& oid, const char *name, bufferptr &bp)
 {
   dout(15) << "getattr " << cid << "/" << oid << " '" << name << "'" << dendl;
   FDRef fd;
@@ -3422,7 +3423,7 @@ int FileStore::getattr(coll_t cid, const hobject_t& oid, const char *name, buffe
   }
 }
 
-int FileStore::getattrs(coll_t cid, const hobject_t& oid, map<string,bufferptr>& aset, bool user_only) 
+int FileStore::getattrs(coll_t cid, const ghobject_t& oid, map<string,bufferptr>& aset, bool user_only)
 {
   dout(15) << "getattrs " << cid << "/" << oid << dendl;
   FDRef fd;
@@ -3481,7 +3482,7 @@ int FileStore::getattrs(coll_t cid, const hobject_t& oid, map<string,bufferptr>&
   }
 }
 
-int FileStore::_setattrs(coll_t cid, const hobject_t& oid, map<string,bufferptr>& aset,
+int FileStore::_setattrs(coll_t cid, const ghobject_t& oid, map<string,bufferptr>& aset,
 			 const SequencerPosition &spos)
 {
   map<string, bufferlist> omap_set;
@@ -3566,7 +3567,7 @@ int FileStore::_setattrs(coll_t cid, const hobject_t& oid, map<string,bufferptr>
 }
 
 
-int FileStore::_rmattr(coll_t cid, const hobject_t& oid, const char *name,
+int FileStore::_rmattr(coll_t cid, const ghobject_t& oid, const char *name,
 		       const SequencerPosition &spos)
 {
   dout(15) << "rmattr " << cid << "/" << oid << " '" << name << "'" << dendl;
@@ -3601,7 +3602,7 @@ int FileStore::_rmattr(coll_t cid, const hobject_t& oid, const char *name,
   return r;
 }
 
-int FileStore::_rmattrs(coll_t cid, const hobject_t& oid,
+int FileStore::_rmattrs(coll_t cid, const ghobject_t& oid,
 			const SequencerPosition &spos)
 {
   dout(15) << "rmattrs " << cid << "/" << oid << dendl;
@@ -3797,14 +3798,14 @@ int FileStore::_collection_remove_recursive(const coll_t &cid,
     return r;
   }
 
-  vector<hobject_t> objects;
-  hobject_t max;
+  vector<ghobject_t> objects;
+  ghobject_t max;
   r = 0;
   while (!max.is_max()) {
     r = collection_list_partial(cid, max, 200, 300, 0, &objects, &max);
     if (r < 0)
       return r;
-    for (vector<hobject_t>::iterator i = objects.begin();
+    for (vector<ghobject_t>::iterator i = objects.begin();
 	 i != objects.end();
 	 ++i) {
       assert(_check_replay_guard(cid, *i, spos));
@@ -3969,9 +3970,9 @@ bool FileStore::collection_empty(coll_t c)
   int r = get_index(c, &index);
   if (r < 0)
     return false;
-  vector<hobject_t> ls;
+  vector<ghobject_t> ls;
   collection_list_handle_t handle;
-  r = index->collection_list_partial(hobject_t(), 1, 1, 0, &ls, NULL);
+  r = index->collection_list_partial(ghobject_t(), 1, 1, 0, &ls, NULL);
   if (r < 0) {
     assert(!m_filestore_fail_eio || r != -EIO);
     return false;
@@ -3979,14 +3980,14 @@ bool FileStore::collection_empty(coll_t c)
   return ls.empty();
 }
 
-int FileStore::collection_list_range(coll_t c, hobject_t start, hobject_t end,
-                                     snapid_t seq, vector<hobject_t> *ls)
+int FileStore::collection_list_range(coll_t c, ghobject_t start, ghobject_t end,
+                                     snapid_t seq, vector<ghobject_t> *ls)
 {
   bool done = false;
-  hobject_t next = start;
+  ghobject_t next = start;
 
   while (!done) {
-    vector<hobject_t> next_objects;
+    vector<ghobject_t> next_objects;
     int r = collection_list_partial(c, next,
                                 get_ideal_list_min(), get_ideal_list_max(),
                                 seq, &next_objects, &next);
@@ -4013,9 +4014,9 @@ int FileStore::collection_list_range(coll_t c, hobject_t start, hobject_t end,
   return 0;
 }
 
-int FileStore::collection_list_partial(coll_t c, hobject_t start,
+int FileStore::collection_list_partial(coll_t c, ghobject_t start,
 				       int min, int max, snapid_t seq,
-				       vector<hobject_t> *ls, hobject_t *next)
+				       vector<ghobject_t> *ls, ghobject_t *next)
 {
   Index index;
   int r = get_index(c, &index);
@@ -4031,7 +4032,7 @@ int FileStore::collection_list_partial(coll_t c, hobject_t start,
   return 0;
 }
 
-int FileStore::collection_list(coll_t c, vector<hobject_t>& ls) 
+int FileStore::collection_list(coll_t c, vector<ghobject_t>& ls)
 {  
   Index index;
   int r = get_index(c, &index);
@@ -4042,7 +4043,7 @@ int FileStore::collection_list(coll_t c, vector<hobject_t>& ls)
   return r;
 }
 
-int FileStore::omap_get(coll_t c, const hobject_t &hoid,
+int FileStore::omap_get(coll_t c, const ghobject_t &hoid,
 			bufferlist *header,
 			map<string, bufferlist> *out)
 {
@@ -4061,7 +4062,7 @@ int FileStore::omap_get(coll_t c, const hobject_t &hoid,
 
 int FileStore::omap_get_header(
   coll_t c,
-  const hobject_t &hoid,
+  const ghobject_t &hoid,
   bufferlist *bl,
   bool allow_eio)
 {
@@ -4078,7 +4079,7 @@ int FileStore::omap_get_header(
   return 0;
 }
 
-int FileStore::omap_get_keys(coll_t c, const hobject_t &hoid, set<string> *keys)
+int FileStore::omap_get_keys(coll_t c, const ghobject_t &hoid, set<string> *keys)
 {
   dout(15) << __func__ << " " << c << "/" << hoid << dendl;
   IndexedPath path;
@@ -4093,7 +4094,7 @@ int FileStore::omap_get_keys(coll_t c, const hobject_t &hoid, set<string> *keys)
   return 0;
 }
 
-int FileStore::omap_get_values(coll_t c, const hobject_t &hoid,
+int FileStore::omap_get_values(coll_t c, const ghobject_t &hoid,
 			       const set<string> &keys,
 			       map<string, bufferlist> *out)
 {
@@ -4110,7 +4111,7 @@ int FileStore::omap_get_values(coll_t c, const hobject_t &hoid,
   return 0;
 }
 
-int FileStore::omap_check_keys(coll_t c, const hobject_t &hoid,
+int FileStore::omap_check_keys(coll_t c, const ghobject_t &hoid,
 			       const set<string> &keys,
 			       set<string> *out)
 {
@@ -4128,7 +4129,7 @@ int FileStore::omap_check_keys(coll_t c, const hobject_t &hoid,
 }
 
 ObjectMap::ObjectMapIterator FileStore::get_omap_iterator(coll_t c,
-							  const hobject_t &hoid)
+							  const ghobject_t &hoid)
 {
   dout(15) << __func__ << " " << c << "/" << hoid << dendl;
   IndexedPath path;
@@ -4199,7 +4200,7 @@ int FileStore::_destroy_collection(coll_t c)
 }
 
 
-int FileStore::_collection_add(coll_t c, coll_t oldcid, const hobject_t& o,
+int FileStore::_collection_add(coll_t c, coll_t oldcid, const ghobject_t& o,
 			       const SequencerPosition& spos)
 {
   dout(15) << "collection_add " << c << "/" << o << " from " << oldcid << "/" << o << dendl;
@@ -4247,8 +4248,8 @@ int FileStore::_collection_add(coll_t c, coll_t oldcid, const hobject_t& o,
   return r;
 }
 
-int FileStore::_collection_move_rename(coll_t oldcid, const hobject_t& oldoid,
-				       coll_t c, const hobject_t& o,
+int FileStore::_collection_move_rename(coll_t oldcid, const ghobject_t& oldoid,
+				       coll_t c, const ghobject_t& o,
 				       const SequencerPosition& spos)
 {
   dout(15) << __func__ << " " << c << "/" << o << " from " << oldcid << "/" << oldoid << dendl;
@@ -4327,7 +4328,7 @@ void FileStore::_inject_failure()
   }
 }
 
-int FileStore::_omap_clear(coll_t cid, const hobject_t &hoid,
+int FileStore::_omap_clear(coll_t cid, const ghobject_t &hoid,
 			   const SequencerPosition &spos) {
   dout(15) << __func__ << " " << cid << "/" << hoid << dendl;
   IndexedPath path;
@@ -4340,7 +4341,7 @@ int FileStore::_omap_clear(coll_t cid, const hobject_t &hoid,
   return 0;
 }
 
-int FileStore::_omap_setkeys(coll_t cid, const hobject_t &hoid,
+int FileStore::_omap_setkeys(coll_t cid, const ghobject_t &hoid,
 			     const map<string, bufferlist> &aset,
 			     const SequencerPosition &spos) {
   dout(15) << __func__ << " " << cid << "/" << hoid << dendl;
@@ -4351,7 +4352,7 @@ int FileStore::_omap_setkeys(coll_t cid, const hobject_t &hoid,
   return object_map->set_keys(hoid, aset, &spos);
 }
 
-int FileStore::_omap_rmkeys(coll_t cid, const hobject_t &hoid,
+int FileStore::_omap_rmkeys(coll_t cid, const ghobject_t &hoid,
 			    const set<string> &keys,
 			    const SequencerPosition &spos) {
   dout(15) << __func__ << " " << cid << "/" << hoid << dendl;
@@ -4365,7 +4366,7 @@ int FileStore::_omap_rmkeys(coll_t cid, const hobject_t &hoid,
   return 0;
 }
 
-int FileStore::_omap_rmkeyrange(coll_t cid, const hobject_t &hoid,
+int FileStore::_omap_rmkeyrange(coll_t cid, const ghobject_t &hoid,
 				const string& first, const string& last,
 				const SequencerPosition &spos) {
   dout(15) << __func__ << " " << cid << "/" << hoid << " [" << first << "," << last << "]" << dendl;
@@ -4382,7 +4383,7 @@ int FileStore::_omap_rmkeyrange(coll_t cid, const hobject_t &hoid,
   return _omap_rmkeys(cid, hoid, keys, spos);
 }
 
-int FileStore::_omap_setheader(coll_t cid, const hobject_t &hoid,
+int FileStore::_omap_setheader(coll_t cid, const ghobject_t &hoid,
 			       const bufferlist &bl,
 			       const SequencerPosition &spos)
 {
@@ -4442,8 +4443,8 @@ int FileStore::_split_collection(coll_t cid,
     _close_replay_guard(dest, spos);
   }
   if (g_conf->filestore_debug_verify_split) {
-    vector<hobject_t> objects;
-    hobject_t next;
+    vector<ghobject_t> objects;
+    ghobject_t next;
     while (1) {
       collection_list_partial(
 	cid,
@@ -4453,7 +4454,7 @@ int FileStore::_split_collection(coll_t cid,
 	&next);
       if (objects.empty())
 	break;
-      for (vector<hobject_t>::iterator i = objects.begin();
+      for (vector<ghobject_t>::iterator i = objects.begin();
 	   i != objects.end();
 	   ++i) {
 	dout(20) << __func__ << ": " << *i << " still in source "
@@ -4462,7 +4463,7 @@ int FileStore::_split_collection(coll_t cid,
       }
       objects.clear();
     }
-    next = hobject_t();
+    next = ghobject_t();
     while (1) {
       collection_list_partial(
 	dest,
@@ -4472,7 +4473,7 @@ int FileStore::_split_collection(coll_t cid,
 	&next);
       if (objects.empty())
 	break;
-      for (vector<hobject_t>::iterator i = objects.begin();
+      for (vector<ghobject_t>::iterator i = objects.begin();
 	   i != objects.end();
 	   ++i) {
 	dout(20) << __func__ << ": " << *i << " now in dest "
diff --git a/src/os/FileStore.h b/src/os/FileStore.h
index 3d154dafb4c..d805b02fc5e 100644
--- a/src/os/FileStore.h
+++ b/src/os/FileStore.h
@@ -307,19 +307,19 @@ private:
   PerfCounters *logger;
 
 public:
-  int lfn_find(coll_t cid, const hobject_t& oid, IndexedPath *path);
-  int lfn_truncate(coll_t cid, const hobject_t& oid, off_t length);
-  int lfn_stat(coll_t cid, const hobject_t& oid, struct stat *buf);
+  int lfn_find(coll_t cid, const ghobject_t& oid, IndexedPath *path);
+  int lfn_truncate(coll_t cid, const ghobject_t& oid, off_t length);
+  int lfn_stat(coll_t cid, const ghobject_t& oid, struct stat *buf);
   int lfn_open(
     coll_t cid,
-    const hobject_t& oid,
+    const ghobject_t& oid,
     bool create,
     FDRef *outfd,
     IndexedPath *path = 0,
     Index *index = 0);
   void lfn_close(FDRef fd);
-  int lfn_link(coll_t c, coll_t newcid, const hobject_t& o, const hobject_t& newoid) ;
-  int lfn_unlink(coll_t cid, const hobject_t& o, const SequencerPosition &spos,
+  int lfn_link(coll_t c, coll_t newcid, const ghobject_t& o, const ghobject_t& newoid) ;
+  int lfn_unlink(coll_t cid, const ghobject_t& o, const SequencerPosition &spos,
 		 bool force_clear_omap=false);
 
 public:
@@ -367,7 +367,7 @@ public:
    */
   void _set_replay_guard(int fd,
 			 const SequencerPosition& spos,
-			 const hobject_t *hoid=0,
+			 const ghobject_t *oid=0,
 			 bool in_progress=false);
   void _set_replay_guard(coll_t cid,
                          const SequencerPosition& spos,
@@ -397,42 +397,42 @@ public:
    */
   int _check_replay_guard(int fd, const SequencerPosition& spos);
   int _check_replay_guard(coll_t cid, const SequencerPosition& spos);
-  int _check_replay_guard(coll_t cid, hobject_t oid, const SequencerPosition& pos);
+  int _check_replay_guard(coll_t cid, ghobject_t oid, const SequencerPosition& pos);
   int _check_global_replay_guard(coll_t cid, const SequencerPosition& spos);
 
   // ------------------
   // objects
-  int pick_object_revision_lt(hobject_t& oid) {
+  int pick_object_revision_lt(ghobject_t& oid) {
     return 0;
   }
-  bool exists(coll_t cid, const hobject_t& oid);
+  bool exists(coll_t cid, const ghobject_t& oid);
   int stat(
     coll_t cid,
-    const hobject_t& oid,
+    const ghobject_t& oid,
     struct stat *st,
     bool allow_eio = false);
   int read(
     coll_t cid,
-    const hobject_t& oid,
+    const ghobject_t& oid,
     uint64_t offset,
     size_t len,
     bufferlist& bl,
     bool allow_eio = false);
-  int fiemap(coll_t cid, const hobject_t& oid, uint64_t offset, size_t len, bufferlist& bl);
+  int fiemap(coll_t cid, const ghobject_t& oid, uint64_t offset, size_t len, bufferlist& bl);
 
-  int _touch(coll_t cid, const hobject_t& oid);
-  int _write(coll_t cid, const hobject_t& oid, uint64_t offset, size_t len, const bufferlist& bl,
+  int _touch(coll_t cid, const ghobject_t& oid);
+  int _write(coll_t cid, const ghobject_t& oid, uint64_t offset, size_t len, const bufferlist& bl,
       bool replica = false);
-  int _zero(coll_t cid, const hobject_t& oid, uint64_t offset, size_t len);
-  int _truncate(coll_t cid, const hobject_t& oid, uint64_t size);
-  int _clone(coll_t cid, const hobject_t& oldoid, const hobject_t& newoid,
+  int _zero(coll_t cid, const ghobject_t& oid, uint64_t offset, size_t len);
+  int _truncate(coll_t cid, const ghobject_t& oid, uint64_t size);
+  int _clone(coll_t cid, const ghobject_t& oldoid, const ghobject_t& newoid,
 	     const SequencerPosition& spos);
-  int _clone_range(coll_t cid, const hobject_t& oldoid, const hobject_t& newoid,
+  int _clone_range(coll_t cid, const ghobject_t& oldoid, const ghobject_t& newoid,
 		   uint64_t srcoff, uint64_t len, uint64_t dstoff,
 		   const SequencerPosition& spos);
   int _do_clone_range(int from, int to, uint64_t srcoff, uint64_t len, uint64_t dstoff);
   int _do_copy_range(int from, int to, uint64_t srcoff, uint64_t len, uint64_t dstoff);
-  int _remove(coll_t cid, const hobject_t& oid, const SequencerPosition &spos);
+  int _remove(coll_t cid, const ghobject_t& oid, const SequencerPosition &spos);
 
   int _fgetattr(int fd, const char *name, bufferptr& bp);
   int _fgetattrs(int fd, map<string,bufferptr>& aset, bool user_only);
@@ -456,25 +456,25 @@ public:
 
   // DEBUG read error injection, an object is removed from both on delete()
   Mutex read_error_lock;
-  set<hobject_t> data_error_set; // read() will return -EIO
-  set<hobject_t> mdata_error_set; // getattr(),stat() will return -EIO
-  void inject_data_error(const hobject_t &oid);
-  void inject_mdata_error(const hobject_t &oid);
-  void debug_obj_on_delete(const hobject_t &oid);
-  bool debug_data_eio(const hobject_t &oid);
-  bool debug_mdata_eio(const hobject_t &oid);
+  set<ghobject_t> data_error_set; // read() will return -EIO
+  set<ghobject_t> mdata_error_set; // getattr(),stat() will return -EIO
+  void inject_data_error(const ghobject_t &oid);
+  void inject_mdata_error(const ghobject_t &oid);
+  void debug_obj_on_delete(const ghobject_t &oid);
+  bool debug_data_eio(const ghobject_t &oid);
+  bool debug_mdata_eio(const ghobject_t &oid);
 
   int snapshot(const string& name);
 
   // attrs
-  int getattr(coll_t cid, const hobject_t& oid, const char *name, bufferptr &bp);
-  int getattrs(coll_t cid, const hobject_t& oid, map<string,bufferptr>& aset, bool user_only = false);
+  int getattr(coll_t cid, const ghobject_t& oid, const char *name, bufferptr &bp);
+  int getattrs(coll_t cid, const ghobject_t& oid, map<string,bufferptr>& aset, bool user_only = false);
 
-  int _setattrs(coll_t cid, const hobject_t& oid, map<string,bufferptr>& aset,
+  int _setattrs(coll_t cid, const ghobject_t& oid, map<string,bufferptr>& aset,
 		const SequencerPosition &spos);
-  int _rmattr(coll_t cid, const hobject_t& oid, const char *name,
+  int _rmattr(coll_t cid, const ghobject_t& oid, const char *name,
 	      const SequencerPosition &spos);
-  int _rmattrs(coll_t cid, const hobject_t& oid,
+  int _rmattrs(coll_t cid, const ghobject_t& oid,
 	       const SequencerPosition &spos);
 
   int collection_getattr(coll_t c, const char *name, void *value, size_t size);
@@ -495,35 +495,35 @@ public:
   int collection_stat(coll_t c, struct stat *st);
   bool collection_exists(coll_t c);
   bool collection_empty(coll_t c);
-  int collection_list(coll_t c, vector<hobject_t>& o);
-  int collection_list_partial(coll_t c, hobject_t start,
+  int collection_list(coll_t c, vector<ghobject_t>& oid);
+  int collection_list_partial(coll_t c, ghobject_t start,
 			      int min, int max, snapid_t snap,
-			      vector<hobject_t> *ls, hobject_t *next);
-  int collection_list_range(coll_t c, hobject_t start, hobject_t end,
-                            snapid_t seq, vector<hobject_t> *ls);
+			      vector<ghobject_t> *ls, ghobject_t *next);
+  int collection_list_range(coll_t c, ghobject_t start, ghobject_t end,
+                            snapid_t seq, vector<ghobject_t> *ls);
 
   // omap (see ObjectStore.h for documentation)
-  int omap_get(coll_t c, const hobject_t &hoid, bufferlist *header,
+  int omap_get(coll_t c, const ghobject_t &oid, bufferlist *header,
 	       map<string, bufferlist> *out);
   int omap_get_header(
     coll_t c,
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     bufferlist *out,
     bool allow_eio = false);
-  int omap_get_keys(coll_t c, const hobject_t &hoid, set<string> *keys);
-  int omap_get_values(coll_t c, const hobject_t &hoid, const set<string> &keys,
+  int omap_get_keys(coll_t c, const ghobject_t &oid, set<string> *keys);
+  int omap_get_values(coll_t c, const ghobject_t &oid, const set<string> &keys,
 		      map<string, bufferlist> *out);
-  int omap_check_keys(coll_t c, const hobject_t &hoid, const set<string> &keys,
+  int omap_check_keys(coll_t c, const ghobject_t &oid, const set<string> &keys,
 		      set<string> *out);
-  ObjectMap::ObjectMapIterator get_omap_iterator(coll_t c, const hobject_t &hoid);
+  ObjectMap::ObjectMapIterator get_omap_iterator(coll_t c, const ghobject_t &oid);
 
   int _create_collection(coll_t c);
   int _create_collection(coll_t c, const SequencerPosition &spos);
   int _destroy_collection(coll_t c);
-  int _collection_add(coll_t c, coll_t ocid, const hobject_t& o,
+  int _collection_add(coll_t c, coll_t ocid, const ghobject_t& oid,
 		      const SequencerPosition& spos);
-  int _collection_move_rename(coll_t oldcid, const hobject_t& oldoid,
-			      coll_t c, const hobject_t& o,
+  int _collection_move_rename(coll_t oldcid, const ghobject_t& oldoid,
+			      coll_t c, const ghobject_t& o,
 			      const SequencerPosition& spos);
   void dump_start(const std::string& file);
   void dump_stop();
@@ -533,17 +533,17 @@ private:
   void _inject_failure();
 
   // omap
-  int _omap_clear(coll_t cid, const hobject_t &hoid,
+  int _omap_clear(coll_t cid, const ghobject_t &oid,
 		  const SequencerPosition &spos);
-  int _omap_setkeys(coll_t cid, const hobject_t &hoid,
+  int _omap_setkeys(coll_t cid, const ghobject_t &oid,
 		    const map<string, bufferlist> &aset,
 		    const SequencerPosition &spos);
-  int _omap_rmkeys(coll_t cid, const hobject_t &hoid, const set<string> &keys,
+  int _omap_rmkeys(coll_t cid, const ghobject_t &oid, const set<string> &keys,
 		   const SequencerPosition &spos);
-  int _omap_rmkeyrange(coll_t cid, const hobject_t &hoid,
+  int _omap_rmkeyrange(coll_t cid, const ghobject_t &oid,
 		       const string& first, const string& last,
 		       const SequencerPosition &spos);
-  int _omap_setheader(coll_t cid, const hobject_t &hoid, const bufferlist &bl,
+  int _omap_setheader(coll_t cid, const ghobject_t &oid, const bufferlist &bl,
 		      const SequencerPosition &spos);
   int _split_collection(coll_t cid, uint32_t bits, uint32_t rem, coll_t dest,
                         const SequencerPosition &spos);
diff --git a/src/os/FlatIndex.cc b/src/os/FlatIndex.cc
index db46750e411..d4644abc627 100644
--- a/src/os/FlatIndex.cc
+++ b/src/os/FlatIndex.cc
@@ -134,18 +134,18 @@ static void lfn_translate(const char *path, const char *name, char *new_name, in
   return;
 }
 
-static int append_oname(const hobject_t &oid, char *s, int len)
+static int append_oname(const ghobject_t &oid, char *s, int len)
 {
   //assert(sizeof(oid) == 28);
   char *end = s + len;
   char *t = s + strlen(s);
 
-  const char *i = oid.oid.name.c_str();
+  const char *i = oid.hobj.oid.name.c_str();
   while (*i && t < end) {
     if (*i == '\\') {
       *t++ = '\\';
       *t++ = '\\';      
-    } else if (*i == '.' && i == oid.oid.name.c_str()) {  // only escape leading .
+    } else if (*i == '.' && i == oid.hobj.oid.name.c_str()) {  // only escape leading .
       *t++ = '\\';
       *t++ = '.';
     } else if (*i == '/') {
@@ -158,17 +158,17 @@ static int append_oname(const hobject_t &oid, char *s, int len)
 
   int size = t - s;
 
-  if (oid.snap == CEPH_NOSNAP)
+  if (oid.hobj.snap == CEPH_NOSNAP)
     size += snprintf(t, end - t, "_head");
-  else if (oid.snap == CEPH_SNAPDIR)
+  else if (oid.hobj.snap == CEPH_SNAPDIR)
     size += snprintf(t, end - t, "_snapdir");
   else
-    size += snprintf(t, end - t, "_%llx", (long long unsigned)oid.snap);
+    size += snprintf(t, end - t, "_%llx", (long long unsigned)oid.hobj.snap);
 
   return size;
 }
 
-static bool parse_object(char *s, hobject_t& oid)
+static bool parse_object(char *s, ghobject_t& oid)
 {
   sobject_t o;
   char *bar = s + strlen(s) - 1;
@@ -201,13 +201,13 @@ static bool parse_object(char *s, hobject_t& oid)
       o.snap = CEPH_SNAPDIR;
     else
       o.snap = strtoull(bar+1, &s, 16);
-    oid = hobject_t(o);
+    oid = ghobject_t(hobject_t(o));
     return true;
   }
   return false;
 }
 
-static int lfn_get(const char *coll_path, const hobject_t& oid, char *pathname, int len, char *lfn, int lfn_len, int *exist, int *is_lfn)
+static int lfn_get(const char *coll_path, const ghobject_t& oid, char *pathname, int len, char *lfn, int lfn_len, int *exist, int *is_lfn)
 {
   int i = 0;
   strncpy(pathname, coll_path, len);
@@ -277,7 +277,7 @@ int FlatIndex::init() {
   return 0;
 }
 
-int FlatIndex::created(const hobject_t &hoid, const char *path) {
+int FlatIndex::created(const ghobject_t &hoid, const char *path) {
   char long_name[PATH_MAX];
   long_name[0] = '\0';
   int actual_len = append_oname(hoid, long_name, sizeof(long_name));
@@ -292,7 +292,7 @@ int FlatIndex::created(const hobject_t &hoid, const char *path) {
   return 0;
 }
 
-int FlatIndex::unlink(const hobject_t &o) {
+int FlatIndex::unlink(const ghobject_t &o) {
   char long_fn[PATH_MAX];
   char short_fn[PATH_MAX];
   char short_fn2[PATH_MAX];
@@ -346,7 +346,7 @@ int FlatIndex::unlink(const hobject_t &o) {
   return 0;
 }
 
-int FlatIndex::lookup(const hobject_t &hoid, IndexedPath *path, int *exist) {
+int FlatIndex::lookup(const ghobject_t &hoid, IndexedPath *path, int *exist) {
   char long_fn[PATH_MAX];
   char short_fn[PATH_MAX];
   int r;
@@ -361,7 +361,7 @@ int FlatIndex::lookup(const hobject_t &hoid, IndexedPath *path, int *exist) {
 }
 
 static int get_hobject_from_oinfo(const char *dir, const char *file, 
-				  hobject_t *o) {
+				  ghobject_t *o) {
   char path[PATH_MAX];
   bufferptr bp(PATH_MAX);
   snprintf(path, sizeof(path), "%s/%s", dir, file);
@@ -376,17 +376,17 @@ static int get_hobject_from_oinfo(const char *dir, const char *file,
   return 0;
 }
 
-int FlatIndex::collection_list_partial(const hobject_t &start,
+int FlatIndex::collection_list_partial(const ghobject_t &start,
 				       int min_count,
 				       int max_count,
 				       snapid_t seq,
-				       vector<hobject_t> *ls,
-				       hobject_t *next) {
+				       vector<ghobject_t> *ls,
+				       ghobject_t *next) {
   assert(0); // Should not be called
   return 0;
 }
 
-int FlatIndex::collection_list(vector<hobject_t> *ls) {
+int FlatIndex::collection_list(vector<ghobject_t> *ls) {
   char buf[offsetof(struct dirent, d_name) + PATH_MAX + 1];
   char dir_name[PATH_MAX], new_name[PATH_MAX];
   strncpy(dir_name, base_path.c_str(), sizeof(dir_name));
@@ -397,7 +397,7 @@ int FlatIndex::collection_list(vector<hobject_t> *ls) {
     return -errno;
   
   // first, build (ino, object) list
-  vector< pair<ino_t,hobject_t> > inolist;
+  vector< pair<ino_t,ghobject_t> > inolist;
 
   struct dirent *de;
   while (::readdir_r(dir, (struct dirent *)buf, &de) == 0) {
@@ -407,11 +407,11 @@ int FlatIndex::collection_list(vector<hobject_t> *ls) {
     if (de->d_name[0] == '.')
       continue;
     //cout << "  got object " << de->d_name << std::endl;
-    hobject_t o;
+    ghobject_t o;
     lfn_translate(dir_name, de->d_name, new_name, sizeof(new_name));
     if (parse_object(new_name, o)) {
       get_hobject_from_oinfo(dir_name, de->d_name, &o);
-      inolist.push_back(pair<ino_t,hobject_t>(de->d_ino, o));
+      inolist.push_back(pair<ino_t,ghobject_t>(de->d_ino, o));
       ls->push_back(o);
     }
   }
@@ -422,7 +422,7 @@ int FlatIndex::collection_list(vector<hobject_t> *ls) {
   // build final list
   ls->resize(inolist.size());
   int i = 0;
-  for (vector< pair<ino_t,hobject_t> >::iterator p = inolist.begin(); p != inolist.end(); ++p)
+  for (vector< pair<ino_t,ghobject_t> >::iterator p = inolist.begin(); p != inolist.end(); ++p)
     (*ls)[i++].swap(p->second);
   
   ::closedir(dir);
diff --git a/src/os/FlatIndex.h b/src/os/FlatIndex.h
index 7a10912dc28..657c273468b 100644
--- a/src/os/FlatIndex.h
+++ b/src/os/FlatIndex.h
@@ -52,35 +52,35 @@ public:
 
   /// @see CollectionIndex
   int created(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const char *path
     );
 
   /// @see CollectionIndex
   int unlink(
-    const hobject_t &hoid
+    const ghobject_t &oid
     );
 
   /// @see CollectionIndex
   int lookup(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     IndexedPath *path,
     int *exist
     );
 
   /// @see CollectionIndex
   int collection_list(
-    vector<hobject_t> *ls
+    vector<ghobject_t> *ls
     );
 
   /// @see CollectionIndex
   int collection_list_partial(
-    const hobject_t &start,
+    const ghobject_t &start,
     int min_count,
     int max_count,
     snapid_t seq,
-    vector<hobject_t> *ls,
-    hobject_t *next
+    vector<ghobject_t> *ls,
+    ghobject_t *next
     );
 };
 
diff --git a/src/os/HashIndex.cc b/src/os/HashIndex.cc
index c279bab3a60..ea50cd038ca 100644
--- a/src/os/HashIndex.cc
+++ b/src/os/HashIndex.cc
@@ -66,7 +66,7 @@ int HashIndex::reset_attr(
     return r;
   if (!exists)
     return 0;
-  map<string, hobject_t> objects;
+  map<string, ghobject_t> objects;
   set<string> subdirs;
   r = list_objects(path, 0, 0, &objects);
   if (r < 0)
@@ -98,7 +98,7 @@ int HashIndex::col_split_level(
   int r = from.list_subdirs(path, &subdirs);
   if (r < 0)
     return r;
-  map<string, hobject_t> objects;
+  map<string, ghobject_t> objects;
   r = from.list_objects(path, 0, 0, &objects);
   if (r < 0)
     return r;
@@ -134,8 +134,8 @@ int HashIndex::col_split_level(
   }
 
   /* Then, do the same for each object */
-  map<string, hobject_t> objs_to_move;
-  for (map<string, hobject_t>::iterator i = objects.begin();
+  map<string, ghobject_t> objs_to_move;
+  for (map<string, ghobject_t>::iterator i = objects.begin();
        i != objects.end();
        ++i) {
     if (i->second.match(inbits, match)) {
@@ -199,7 +199,7 @@ int HashIndex::col_split_level(
       return r;
   }
 
-  for (map<string, hobject_t>::iterator i = objs_to_move.begin();
+  for (map<string, ghobject_t>::iterator i = objs_to_move.begin();
        i != objs_to_move.end();
        ++i) {
     from_info.objs--;
@@ -244,7 +244,7 @@ int HashIndex::_init() {
 
 /* LFNIndex virtual method implementations */
 int HashIndex::_created(const vector<string> &path,
-			const hobject_t &hoid,
+			const ghobject_t &oid,
 			const string &mangled_name) {
   subdir_info_s info;
   int r;
@@ -267,10 +267,10 @@ int HashIndex::_created(const vector<string> &path,
 }
 
 int HashIndex::_remove(const vector<string> &path,
-		       const hobject_t &hoid,
+		       const ghobject_t &oid,
 		       const string &mangled_name) {
   int r;
-  r = remove_object(path, hoid);
+  r = remove_object(path, oid);
   if (r < 0)
     return r;
   subdir_info_s info;
@@ -291,12 +291,12 @@ int HashIndex::_remove(const vector<string> &path,
   }
 }
 
-int HashIndex::_lookup(const hobject_t &hoid,
+int HashIndex::_lookup(const ghobject_t &oid,
 		       vector<string> *path,
 		       string *mangled_name,
 		       int *exists_out) {
   vector<string> path_comp;
-  get_path_components(hoid, &path_comp);
+  get_path_components(oid, &path_comp);
   vector<string>::iterator next = path_comp.begin();
   int exists;
   while (1) {
@@ -313,22 +313,22 @@ int HashIndex::_lookup(const hobject_t &hoid,
       break;
     path->push_back(*(next++));
   }
-  return get_mangled_name(*path, hoid, mangled_name, exists_out);
+  return get_mangled_name(*path, oid, mangled_name, exists_out);
 }
 
-int HashIndex::_collection_list(vector<hobject_t> *ls) {
+int HashIndex::_collection_list(vector<ghobject_t> *ls) {
   vector<string> path;
   return list_by_hash(path, 0, 0, 0, 0, ls);
 }
 
-int HashIndex::_collection_list_partial(const hobject_t &start,
+int HashIndex::_collection_list_partial(const ghobject_t &start,
 					int min_count,
 					int max_count,
 					snapid_t seq,
-					vector<hobject_t> *ls,
-					hobject_t *next) {
+					vector<ghobject_t> *ls,
+					ghobject_t *next) {
   vector<string> path;
-  hobject_t _next;
+  ghobject_t _next;
   if (!next)
     next = &_next;
   *next = start;
@@ -345,7 +345,7 @@ int HashIndex::recursive_remove(const vector<string> &path) {
   int r = list_subdirs(path, &subdirs);
   if (r < 0)
     return r;
-  map<string, hobject_t> objects;
+  map<string, ghobject_t> objects;
   r = list_objects(path, 0, 0, &objects);
   if (r < 0)
     return r;
@@ -475,7 +475,7 @@ int HashIndex::initiate_split(const vector<string> &path, subdir_info_s info) {
 
 int HashIndex::complete_split(const vector<string> &path, subdir_info_s info) {
   int level = info.hash_level;
-  map<string, hobject_t> objects;
+  map<string, ghobject_t> objects;
   vector<string> dst = path;
   int r;
   dst.push_back("");
@@ -486,17 +486,17 @@ int HashIndex::complete_split(const vector<string> &path, subdir_info_s info) {
   r = list_subdirs(path, &subdirs);
   if (r < 0)
     return r;
-  map<string, map<string, hobject_t> > mapped;
-  map<string, hobject_t> moved;
+  map<string, map<string, ghobject_t> > mapped;
+  map<string, ghobject_t> moved;
   int num_moved = 0;
-  for (map<string, hobject_t>::iterator i = objects.begin();
+  for (map<string, ghobject_t>::iterator i = objects.begin();
        i != objects.end();
        ++i) {
     vector<string> new_path;
     get_path_components(i->second, &new_path);
     mapped[new_path[level]][i->first] = i->second;
   }
-  for (map<string, map<string, hobject_t> >::iterator i = mapped.begin();
+  for (map<string, map<string, ghobject_t> >::iterator i = mapped.begin();
        i != mapped.end();
        ) {
     dst[level] = i->first;
@@ -505,7 +505,7 @@ int HashIndex::complete_split(const vector<string> &path, subdir_info_s info) {
     subdir_info_s temp;
     // subdir has already been fully copied
     if (subdirs.count(i->first) && !get_info(dst, &temp)) {
-      for (map<string, hobject_t>::iterator j = i->second.begin();
+      for (map<string, ghobject_t>::iterator j = i->second.begin();
 	   j != i->second.end();
 	   ++j) {
 	moved[j->first] = j->second;
@@ -533,7 +533,7 @@ int HashIndex::complete_split(const vector<string> &path, subdir_info_s info) {
 	return r;
     } // else subdir has been created but only partially copied
 
-    for (map<string, hobject_t>::iterator j = i->second.begin();
+    for (map<string, ghobject_t>::iterator j = i->second.begin();
 	 j != i->second.end();
 	 ++j) {
       moved[j->first] = j->second;
@@ -574,12 +574,12 @@ int HashIndex::complete_split(const vector<string> &path, subdir_info_s info) {
   return end_split_or_merge(path);
 }
 
-void HashIndex::get_path_components(const hobject_t &hoid,
+void HashIndex::get_path_components(const ghobject_t &oid,
 				    vector<string> *path) {
   char buf[MAX_HASH_LEVEL + 1];
-  snprintf(buf, sizeof(buf), "%.*X", MAX_HASH_LEVEL, (uint32_t)hoid.get_filestore_key());
+  snprintf(buf, sizeof(buf), "%.*X", MAX_HASH_LEVEL, (uint32_t)oid.hobj.get_filestore_key());
 
-  // Path components are the hex characters of hoid.hash, least
+  // Path components are the hex characters of oid.hobj.hash, least
   // significant first
   for (int i = 0; i < MAX_HASH_LEVEL; ++i) {
     path->push_back(string(&buf[i], 1));
@@ -596,9 +596,9 @@ string HashIndex::get_hash_str(uint32_t hash) {
   return retval;
 }
 
-string HashIndex::get_path_str(const hobject_t &hoid) {
-  assert(!hoid.is_max());
-  return get_hash_str(hoid.hash);
+string HashIndex::get_path_str(const ghobject_t &oid) {
+  assert(!oid.is_max());
+  return get_hash_str(oid.hobj.hash);
 }
 
 uint32_t HashIndex::hash_prefix_to_hash(string prefix) {
@@ -616,12 +616,12 @@ uint32_t HashIndex::hash_prefix_to_hash(string prefix) {
 
 int HashIndex::get_path_contents_by_hash(const vector<string> &path,
 					 const string *lower_bound,
-					 const hobject_t *next_object,
+					 const ghobject_t *next_object,
 					 const snapid_t *seq,
 					 set<string> *hash_prefixes,
-					 set<pair<string, hobject_t> > *objects) {
+					 set<pair<string, ghobject_t> > *objects) {
   set<string> subdirs;
-  map<string, hobject_t> rev_objects;
+  map<string, ghobject_t> rev_objects;
   int r;
   string cur_prefix;
   for (vector<string>::const_iterator i = path.begin();
@@ -632,7 +632,7 @@ int HashIndex::get_path_contents_by_hash(const vector<string> &path,
   r = list_objects(path, 0, 0, &rev_objects);
   if (r < 0)
     return r;
-  for (map<string, hobject_t>::iterator i = rev_objects.begin();
+  for (map<string, ghobject_t>::iterator i = rev_objects.begin();
        i != rev_objects.end();
        ++i) {
     string hash_prefix = get_path_str(i->second);
@@ -640,10 +640,10 @@ int HashIndex::get_path_contents_by_hash(const vector<string> &path,
       continue;
     if (next_object && i->second < *next_object)
       continue;
-    if (seq && i->second.snap < *seq)
+    if (seq && i->second.hobj.snap < *seq)
       continue;
     hash_prefixes->insert(hash_prefix);
-    objects->insert(pair<string, hobject_t>(hash_prefix, i->second));
+    objects->insert(pair<string, ghobject_t>(hash_prefix, i->second));
   }
   r = list_subdirs(path, &subdirs);
   if (r < 0)
@@ -667,13 +667,13 @@ int HashIndex::list_by_hash(const vector<string> &path,
 			    int min_count,
 			    int max_count,
 			    snapid_t seq,
-			    hobject_t *next,
-			    vector<hobject_t> *out) {
+			    ghobject_t *next,
+			    vector<ghobject_t> *out) {
   assert(out);
   vector<string> next_path = path;
   next_path.push_back("");
   set<string> hash_prefixes;
-  set<pair<string, hobject_t> > objects;
+  set<pair<string, ghobject_t> > objects;
   int r = get_path_contents_by_hash(path,
 				    NULL,
 				    next,
@@ -686,16 +686,16 @@ int HashIndex::list_by_hash(const vector<string> &path,
   for (set<string>::iterator i = hash_prefixes.begin();
        i != hash_prefixes.end();
        ++i) {
-    set<pair<string, hobject_t> >::iterator j = objects.lower_bound(
-      make_pair(*i, hobject_t()));
+    set<pair<string, ghobject_t> >::iterator j = objects.lower_bound(
+      make_pair(*i, ghobject_t()));
     if (j == objects.end() || j->first != *i) {
       if (min_count > 0 && out->size() > (unsigned)min_count) {
 	if (next)
-	  *next = hobject_t("", "", CEPH_NOSNAP, hash_prefix_to_hash(*i), -1, "");
+	  *next = ghobject_t(hobject_t("", "", CEPH_NOSNAP, hash_prefix_to_hash(*i), -1, ""));
 	return 0;
       }
       *(next_path.rbegin()) = *(i->rbegin());
-      hobject_t next_recurse;
+      ghobject_t next_recurse;
       if (next)
 	next_recurse = *next;
       r = list_by_hash(next_path,
@@ -727,6 +727,6 @@ int HashIndex::list_by_hash(const vector<string> &path,
     }
   }
   if (next)
-    *next = hobject_t::get_max();
+    *next = ghobject_t(hobject_t::get_max());
   return 0;
 }
diff --git a/src/os/HashIndex.h b/src/os/HashIndex.h
index fcabd9f7198..6f5bca077d4 100644
--- a/src/os/HashIndex.h
+++ b/src/os/HashIndex.h
@@ -39,7 +39,7 @@
  * given by the hex characters in the hash beginning with the least
  * significant.
  * 
- * ex: hobject_t("object", CEPH_NO_SNAP, 0xA4CEE0D2)
+ * ex: ghobject_t("object", CEPH_NO_SNAP, 0xA4CEE0D2)
  * would be located in (root)/2/D/0/
  * 
  * Subdirectories are created when the number of objects in a directory
@@ -163,30 +163,30 @@ protected:
 
   int _created(
     const vector<string> &path,
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const string &mangled_name
     );
   int _remove(
     const vector<string> &path,
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const string &mangled_name
     );
   int _lookup(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     vector<string> *path,
     string *mangled_name,
     int *exists
     );
   int _collection_list(
-    vector<hobject_t> *ls
+    vector<ghobject_t> *ls
     );
   int _collection_list_partial(
-    const hobject_t &start,
+    const ghobject_t &start,
     int min_count,
     int max_count,
     snapid_t seq,
-    vector<hobject_t> *ls,
-    hobject_t *next
+    vector<ghobject_t> *ls,
+    ghobject_t *next
     );
 private:
   /// Recursively remove path and its subdirs
@@ -262,7 +262,7 @@ private:
 
   /// Determine path components from hoid hash
   void get_path_components(
-    const hobject_t &hoid, ///< [in] Object for which to get path components
+    const ghobject_t &oid, ///< [in] Object for which to get path components
     vector<string> *path   ///< [out] Path components for hoid.
     );
 
@@ -278,12 +278,12 @@ private:
     
 
   /** 
-   * Get string representation of hobject_t/hash
+   * Get string representation of ghobject_t/hash
    *
    * e.g: 0x01234567 -> "76543210"
    */
   static string get_path_str(
-    const hobject_t &hoid ///< [in] Object to get hash string for
+    const ghobject_t &oid ///< [in] Object to get hash string for
     ); ///< @return Hash string for hoid.
 
   /// Get string from hash, @see get_path_str
@@ -319,20 +319,20 @@ private:
   int get_path_contents_by_hash(
     const vector<string> &path,            /// [in] Path to list
     const string *lower_bound,             /// [in] list > *lower_bound
-    const hobject_t *next_object,          /// [in] list > *next_object
+    const ghobject_t *next_object,          /// [in] list > *next_object
     const snapid_t *seq,                   /// [in] list >= *seq
     set<string> *hash_prefixes,            /// [out] prefixes in dir
-    set<pair<string, hobject_t> > *objects /// [out] objects
+    set<pair<string, ghobject_t> > *objects /// [out] objects
     );
 
-  /// List objects in collection in hobject_t order
+  /// List objects in collection in ghobject_t order
   int list_by_hash(
     const vector<string> &path, /// [in] Path to list
     int min_count,              /// [in] List at least min_count
     int max_count,              /// [in] List at most max_count
     snapid_t seq,               /// [in] list only objects where snap >= seq
-    hobject_t *next,            /// [in,out] List objects >= *next
-    vector<hobject_t> *out      /// [out] Listed objects
+    ghobject_t *next,            /// [in,out] List objects >= *next
+    vector<ghobject_t> *out      /// [out] Listed objects
     ); ///< @return Error Code, 0 on success
 };
 
diff --git a/src/os/LFNIndex.cc b/src/os/LFNIndex.cc
index 6fec291aa73..83e1c144754 100644
--- a/src/os/LFNIndex.cc
+++ b/src/os/LFNIndex.cc
@@ -73,7 +73,7 @@ int LFNIndex::init()
   return _init();
 }
 
-int LFNIndex::created(const hobject_t &hoid, const char *path)
+int LFNIndex::created(const ghobject_t &oid, const char *path)
 {
   WRAP_RETRY(
   vector<string> path_comp;
@@ -81,39 +81,39 @@ int LFNIndex::created(const hobject_t &hoid, const char *path)
   r = decompose_full_path(path, &path_comp, 0, &short_name);
   if (r < 0)
     goto out;
-  r = lfn_created(path_comp, hoid, short_name);
+  r = lfn_created(path_comp, oid, short_name);
   if (r < 0)
     goto out;
-  r = _created(path_comp, hoid, short_name);
+  r = _created(path_comp, oid, short_name);
   if (r < 0)
     goto out;
     );
 }
 
-int LFNIndex::unlink(const hobject_t &hoid)
+int LFNIndex::unlink(const ghobject_t &oid)
 {
   WRAP_RETRY(
   vector<string> path;
   string short_name;
-  r = _lookup(hoid, &path, &short_name, NULL);
+  r = _lookup(oid, &path, &short_name, NULL);
   if (r < 0) {
     goto out;
   }
-  r = _remove(path, hoid, short_name);
+  r = _remove(path, oid, short_name);
   if (r < 0) {
     goto out;
   }
   );
 }
 
-int LFNIndex::lookup(const hobject_t &hoid,
+int LFNIndex::lookup(const ghobject_t &oid,
 		     IndexedPath *out_path,
 		     int *exist)
 {
   WRAP_RETRY(
   vector<string> path;
   string short_name;
-  r = _lookup(hoid, &path, &short_name, exist);
+  r = _lookup(oid, &path, &short_name, exist);
   if (r < 0)
     goto out;
   string full_path = get_full_path(path, short_name);
@@ -136,18 +136,18 @@ int LFNIndex::lookup(const hobject_t &hoid,
   );
 }
 
-int LFNIndex::collection_list(vector<hobject_t> *ls)
+int LFNIndex::collection_list(vector<ghobject_t> *ls)
 {
   return _collection_list(ls);
 }
 
 
-int LFNIndex::collection_list_partial(const hobject_t &start,
+int LFNIndex::collection_list_partial(const ghobject_t &start,
 				      int min_count,
 				      int max_count,
 				      snapid_t seq,
-				      vector<hobject_t> *ls,
-				      hobject_t *next)
+				      vector<ghobject_t> *ls,
+				      ghobject_t *next)
 {
   return _collection_list_partial(start, min_count, max_count, seq, ls, next);
 }
@@ -172,14 +172,14 @@ int LFNIndex::fsync_dir(const vector<string> &path)
 
 int LFNIndex::link_object(const vector<string> &from,
 			  const vector<string> &to,
-			  const hobject_t &hoid,
+			  const ghobject_t &oid,
 			  const string &from_short_name)
 {
   int r;
   string from_path = get_full_path(from, from_short_name);
   string to_path;
   maybe_inject_failure();
-  r = lfn_get_name(to, hoid, 0, &to_path, 0);
+  r = lfn_get_name(to, oid, 0, &to_path, 0);
   if (r < 0)
     return r;
   maybe_inject_failure();
@@ -192,11 +192,11 @@ int LFNIndex::link_object(const vector<string> &from,
 }
 
 int LFNIndex::remove_objects(const vector<string> &dir,
-			     const map<string, hobject_t> &to_remove,
-			     map<string, hobject_t> *remaining)
+			     const map<string, ghobject_t> &to_remove,
+			     map<string, ghobject_t> *remaining)
 {
   set<string> clean_chains;
-  for (map<string, hobject_t>::const_iterator to_clean = to_remove.begin();
+  for (map<string, ghobject_t>::const_iterator to_clean = to_remove.begin();
        to_clean != to_remove.end();
        ++to_clean) {
     if (!lfn_is_hashed_filename(to_clean->first)) {
@@ -210,7 +210,7 @@ int LFNIndex::remove_objects(const vector<string> &dir,
     if (clean_chains.count(lfn_get_short_name(to_clean->second, 0)))
       continue;
     set<int> holes;
-    map<int, pair<string, hobject_t> > chain;
+    map<int, pair<string, ghobject_t> > chain;
     for (int i = 0; ; ++i) {
       string short_name = lfn_get_short_name(to_clean->second, i);
       if (remaining->count(short_name)) {
@@ -222,7 +222,7 @@ int LFNIndex::remove_objects(const vector<string> &dir,
       }
     }
 
-    map<int, pair<string, hobject_t > >::reverse_iterator candidate = chain.rbegin();
+    map<int, pair<string, ghobject_t > >::reverse_iterator candidate = chain.rbegin();
     for (set<int>::iterator i = holes.begin();
 	 i != holes.end();
 	 ++i) {
@@ -244,7 +244,7 @@ int LFNIndex::remove_objects(const vector<string> &dir,
       if (r < 0)
 	return -errno;
       remaining->erase(candidate->second.first);
-      remaining->insert(pair<string, hobject_t>(
+      remaining->insert(pair<string, ghobject_t>(
 			  lfn_get_short_name(candidate->second.second, *i),
 					     candidate->second.second));
       ++candidate;
@@ -258,12 +258,12 @@ int LFNIndex::remove_objects(const vector<string> &dir,
 int LFNIndex::move_objects(const vector<string> &from,
 			   const vector<string> &to)
 {
-  map<string, hobject_t> to_move;
+  map<string, ghobject_t> to_move;
   int r;
   r = list_objects(from, 0, NULL, &to_move);
   if (r < 0)
     return r;
-  for (map<string,hobject_t>::iterator i = to_move.begin();
+  for (map<string,ghobject_t>::iterator i = to_move.begin();
        i != to_move.end();
        ++i) {
     string from_path = get_full_path(from, i->first);
@@ -284,7 +284,7 @@ int LFNIndex::move_objects(const vector<string> &from,
   r = fsync_dir(to);
   if (r < 0)
     return r;
-  for (map<string,hobject_t>::iterator i = to_move.begin();
+  for (map<string,ghobject_t>::iterator i = to_move.begin();
        i != to_move.end();
        ++i) {
     maybe_inject_failure();
@@ -297,23 +297,23 @@ int LFNIndex::move_objects(const vector<string> &from,
 }
 
 int LFNIndex::remove_object(const vector<string> &from,
-			    const hobject_t &hoid)
+			    const ghobject_t &oid)
 {
   string short_name;
   int r, exist;
   maybe_inject_failure();
-  r = get_mangled_name(from, hoid, &short_name, &exist);
+  r = get_mangled_name(from, oid, &short_name, &exist);
   maybe_inject_failure();
   if (r < 0)
     return r;
-  return lfn_unlink(from, hoid, short_name);
+  return lfn_unlink(from, oid, short_name);
 }
 
 int LFNIndex::get_mangled_name(const vector<string> &from,
-			       const hobject_t &hoid,
+			       const ghobject_t &oid,
 			       string *mangled_name, int *exists)
 {
-  return lfn_get_name(from, hoid, mangled_name, 0, exists);
+  return lfn_get_name(from, oid, mangled_name, 0, exists);
 }
 
 int LFNIndex::move_subdir(
@@ -337,7 +337,7 @@ int LFNIndex::move_object(
   LFNIndex &from,
   LFNIndex &dest,
   const vector<string> &path,
-  const pair<string, hobject_t> &obj
+  const pair<string, ghobject_t> &obj
   )
 {
   string from_path(from.get_full_path(path, obj.first));
@@ -366,7 +366,7 @@ int LFNIndex::move_object(
 
 
 static int get_hobject_from_oinfo(const char *dir, const char *file, 
-				  hobject_t *o)
+				  ghobject_t *o)
 {
   char path[PATH_MAX];
   bufferptr bp(PATH_MAX);
@@ -384,7 +384,7 @@ static int get_hobject_from_oinfo(const char *dir, const char *file,
 
 
 int LFNIndex::list_objects(const vector<string> &to_list, int max_objs,
-			   long *handle, map<string, hobject_t> *out)
+			   long *handle, map<string, ghobject_t> *out)
 {
   string to_list_path = get_full_path_subdir(to_list);
   DIR *dir = ::opendir(to_list_path.c_str());
@@ -412,7 +412,7 @@ int LFNIndex::list_objects(const vector<string> &to_list, int max_objs,
     if (de->d_name[0] == '.')
       continue;
     string short_name(de->d_name);
-    hobject_t obj;
+    ghobject_t obj;
     if (lfn_is_object(short_name)) {
       r = lfn_translate(to_list, short_name, &obj);
       if (r < 0) {
@@ -426,7 +426,7 @@ int LFNIndex::list_objects(const vector<string> &to_list, int max_objs,
 	if (index_version == HASH_INDEX_TAG)
 	  get_hobject_from_oinfo(to_list_path.c_str(), short_name.c_str(), &obj);
 	  
-	out->insert(pair<string, hobject_t>(short_name, obj));
+	out->insert(pair<string, ghobject_t>(short_name, obj));
 	++listed;
       } else {
 	continue;
@@ -460,7 +460,7 @@ int LFNIndex::list_subdirs(const vector<string> &to_list,
     }
     string short_name(de->d_name);
     string demangled_name;
-    hobject_t obj;
+    ghobject_t obj;
     if (lfn_is_subdir(short_name, &demangled_name)) {
       out->insert(demangled_name);
     }
@@ -557,15 +557,16 @@ int LFNIndex::remove_attr_path(const vector<string> &path,
   return chain_removexattr(full_path.c_str(), mangled_attr_name.c_str());
 }
   
-string LFNIndex::lfn_generate_object_name_keyless(const hobject_t &hoid)
+string LFNIndex::lfn_generate_object_name_keyless(const ghobject_t &oid)
 {
   char s[FILENAME_MAX_LEN];
   char *end = s + sizeof(s);
   char *t = s;
 
-  const char *i = hoid.oid.name.c_str();
+  assert(oid.generation == ghobject_t::NO_GEN);
+  const char *i = oid.hobj.oid.name.c_str();
   // Escape subdir prefix
-  if (hoid.oid.name.substr(0, 4) == "DIR_") {
+  if (oid.hobj.oid.name.substr(0, 4) == "DIR_") {
     *t++ = '\\';
     *t++ = 'd';
     i += 4;
@@ -574,7 +575,7 @@ string LFNIndex::lfn_generate_object_name_keyless(const hobject_t &hoid)
     if (*i == '\\') {
       *t++ = '\\';
       *t++ = '\\';      
-    } else if (*i == '.' && i == hoid.oid.name.c_str()) {  // only escape leading .
+    } else if (*i == '.' && i == oid.hobj.oid.name.c_str()) {  // only escape leading .
       *t++ = '\\';
       *t++ = '.';
     } else if (*i == '/') {
@@ -585,13 +586,13 @@ string LFNIndex::lfn_generate_object_name_keyless(const hobject_t &hoid)
     i++;
   }
 
-  if (hoid.snap == CEPH_NOSNAP)
+  if (oid.hobj.snap == CEPH_NOSNAP)
     t += snprintf(t, end - t, "_head");
-  else if (hoid.snap == CEPH_SNAPDIR)
+  else if (oid.hobj.snap == CEPH_SNAPDIR)
     t += snprintf(t, end - t, "_snapdir");
   else
-    t += snprintf(t, end - t, "_%llx", (long long unsigned)hoid.snap);
-  snprintf(t, end - t, "_%.*X", (int)(sizeof(hoid.hash)*2), hoid.hash);
+    t += snprintf(t, end - t, "_%llx", (long long unsigned)oid.hobj.snap);
+  snprintf(t, end - t, "_%.*X", (int)(sizeof(oid.hobj.hash)*2), oid.hobj.hash);
 
   return string(s);
 }
@@ -615,94 +616,112 @@ static void append_escaped(string::const_iterator begin,
   }
 }
 
-string LFNIndex::lfn_generate_object_name(const hobject_t &hoid)
+string LFNIndex::lfn_generate_object_name(const ghobject_t &oid)
 {
   if (index_version == HASH_INDEX_TAG)
-    return lfn_generate_object_name_keyless(hoid);
+    return lfn_generate_object_name_keyless(oid);
   if (index_version == HASH_INDEX_TAG_2)
-    return lfn_generate_object_name_poolless(hoid);
+    return lfn_generate_object_name_poolless(oid);
 
   string full_name;
-  string::const_iterator i = hoid.oid.name.begin();
-  if (hoid.oid.name.substr(0, 4) == "DIR_") {
+  string::const_iterator i = oid.hobj.oid.name.begin();
+  if (oid.hobj.oid.name.substr(0, 4) == "DIR_") {
     full_name.append("\\d");
     i += 4;
-  } else if (hoid.oid.name[0] == '.') {
+  } else if (oid.hobj.oid.name[0] == '.') {
     full_name.append("\\.");
     ++i;
   }
-  append_escaped(i, hoid.oid.name.end(), &full_name);
+  append_escaped(i, oid.hobj.oid.name.end(), &full_name);
   full_name.append("_");
-  append_escaped(hoid.get_key().begin(), hoid.get_key().end(), &full_name);
+  append_escaped(oid.hobj.get_key().begin(), oid.hobj.get_key().end(), &full_name);
   full_name.append("_");
 
   char buf[PATH_MAX];
   char *t = buf;
   char *end = t + sizeof(buf);
-  if (hoid.snap == CEPH_NOSNAP)
+  if (oid.hobj.snap == CEPH_NOSNAP)
     t += snprintf(t, end - t, "head");
-  else if (hoid.snap == CEPH_SNAPDIR)
+  else if (oid.hobj.snap == CEPH_SNAPDIR)
     t += snprintf(t, end - t, "snapdir");
   else
-    t += snprintf(t, end - t, "%llx", (long long unsigned)hoid.snap);
-  snprintf(t, end - t, "_%.*X", (int)(sizeof(hoid.hash)*2), hoid.hash);
+    t += snprintf(t, end - t, "%llx", (long long unsigned)oid.hobj.snap);
+  snprintf(t, end - t, "_%.*X", (int)(sizeof(oid.hobj.hash)*2), oid.hobj.hash);
   full_name += string(buf);
   full_name.append("_");
 
-  append_escaped(hoid.nspace.begin(), hoid.nspace.end(), &full_name);
+  append_escaped(oid.hobj.nspace.begin(), oid.hobj.nspace.end(), &full_name);
   full_name.append("_");
 
   t = buf;
   end = t + sizeof(buf);
-  if (hoid.pool == -1)
+  if (oid.hobj.pool == -1)
     t += snprintf(t, end - t, "none");
   else
-    t += snprintf(t, end - t, "%llx", (long long unsigned)hoid.pool);
+    t += snprintf(t, end - t, "%llx", (long long unsigned)oid.hobj.pool);
   full_name += string(buf);
 
+  if (oid.generation != ghobject_t::NO_GEN) {
+    assert(oid.shard_id != ghobject_t::NO_SHARD);
+    full_name.append("_");
+
+    t = buf;
+    end = t + sizeof(buf);
+    t += snprintf(t, end - t, "%llx", (long long unsigned)oid.generation);
+    full_name += string(buf);
+
+    full_name.append("_");
+
+    t = buf;
+    end = t + sizeof(buf);
+    t += snprintf(t, end - t, "%x", (int)oid.shard_id);
+    full_name += string(buf);
+  }
+
   return full_name;
 }
 
-string LFNIndex::lfn_generate_object_name_poolless(const hobject_t &hoid)
+string LFNIndex::lfn_generate_object_name_poolless(const ghobject_t &oid)
 {
   if (index_version == HASH_INDEX_TAG)
-    return lfn_generate_object_name_keyless(hoid);
+    return lfn_generate_object_name_keyless(oid);
 
+  assert(oid.generation == ghobject_t::NO_GEN);
   string full_name;
-  string::const_iterator i = hoid.oid.name.begin();
-  if (hoid.oid.name.substr(0, 4) == "DIR_") {
+  string::const_iterator i = oid.hobj.oid.name.begin();
+  if (oid.hobj.oid.name.substr(0, 4) == "DIR_") {
     full_name.append("\\d");
     i += 4;
-  } else if (hoid.oid.name[0] == '.') {
+  } else if (oid.hobj.oid.name[0] == '.') {
     full_name.append("\\.");
     ++i;
   }
-  append_escaped(i, hoid.oid.name.end(), &full_name);
+  append_escaped(i, oid.hobj.oid.name.end(), &full_name);
   full_name.append("_");
-  append_escaped(hoid.get_key().begin(), hoid.get_key().end(), &full_name);
+  append_escaped(oid.hobj.get_key().begin(), oid.hobj.get_key().end(), &full_name);
   full_name.append("_");
 
   char snap_with_hash[PATH_MAX];
   char *t = snap_with_hash;
   char *end = t + sizeof(snap_with_hash);
-  if (hoid.snap == CEPH_NOSNAP)
+  if (oid.hobj.snap == CEPH_NOSNAP)
     t += snprintf(t, end - t, "head");
-  else if (hoid.snap == CEPH_SNAPDIR)
+  else if (oid.hobj.snap == CEPH_SNAPDIR)
     t += snprintf(t, end - t, "snapdir");
   else
-    t += snprintf(t, end - t, "%llx", (long long unsigned)hoid.snap);
-  snprintf(t, end - t, "_%.*X", (int)(sizeof(hoid.hash)*2), hoid.hash);
+    t += snprintf(t, end - t, "%llx", (long long unsigned)oid.hobj.snap);
+  snprintf(t, end - t, "_%.*X", (int)(sizeof(oid.hobj.hash)*2), oid.hobj.hash);
   full_name += string(snap_with_hash);
   return full_name;
 }
 
 int LFNIndex::lfn_get_name(const vector<string> &path, 
-			   const hobject_t &hoid,
+			   const ghobject_t &oid,
 			   string *mangled_name, string *out_path,
 			   int *exists)
 {
   string subdir_path = get_full_path_subdir(path);
-  string full_name = lfn_generate_object_name(hoid);
+  string full_name = lfn_generate_object_name(oid);
   int r;
 
   if (!lfn_must_hash(full_name)) {
@@ -732,7 +751,7 @@ int LFNIndex::lfn_get_name(const vector<string> &path,
   string candidate_path;
   char buf[FILENAME_MAX_LEN + 1];
   for ( ; ; ++i) {
-    candidate = lfn_get_short_name(hoid, i);
+    candidate = lfn_get_short_name(oid, i);
     candidate_path = get_full_path(path, candidate);
     r = chain_getxattr(candidate_path.c_str(), get_lfn_attr().c_str(), buf, sizeof(buf));
     if (r < 0) {
@@ -771,20 +790,20 @@ int LFNIndex::lfn_get_name(const vector<string> &path,
 }
 
 int LFNIndex::lfn_created(const vector<string> &path,
-			  const hobject_t &hoid,
+			  const ghobject_t &oid,
 			  const string &mangled_name)
 {
   if (!lfn_is_hashed_filename(mangled_name))
     return 0;
   string full_path = get_full_path(path, mangled_name);
-  string full_name = lfn_generate_object_name(hoid);
+  string full_name = lfn_generate_object_name(oid);
   maybe_inject_failure();
   return chain_setxattr(full_path.c_str(), get_lfn_attr().c_str(), 
 		     full_name.c_str(), full_name.size());
 }
 
 int LFNIndex::lfn_unlink(const vector<string> &path,
-			 const hobject_t &hoid,
+			 const ghobject_t &oid,
 			 const string &mangled_name)
 {
   if (!lfn_is_hashed_filename(mangled_name)) {
@@ -801,7 +820,7 @@ int LFNIndex::lfn_unlink(const vector<string> &path,
   
   int i = 0;
   for ( ; ; ++i) {
-    string candidate = lfn_get_short_name(hoid, i);
+    string candidate = lfn_get_short_name(oid, i);
     if (candidate == mangled_name)
       break;
   }
@@ -809,7 +828,7 @@ int LFNIndex::lfn_unlink(const vector<string> &path,
   ++i;
   for ( ; ; ++i) {
     struct stat buf;
-    string to_check = lfn_get_short_name(hoid, i);
+    string to_check = lfn_get_short_name(oid, i);
     string to_check_path = get_full_path(path, to_check);
     int r = ::stat(to_check_path.c_str(), &buf);
     if (r < 0) {
@@ -831,7 +850,7 @@ int LFNIndex::lfn_unlink(const vector<string> &path,
       return 0;
   } else {
     string rename_to = get_full_path(path, mangled_name);
-    string rename_from = get_full_path(path, lfn_get_short_name(hoid, i - 1));
+    string rename_from = get_full_path(path, lfn_get_short_name(oid, i - 1));
     maybe_inject_failure();
     int r = ::rename(rename_from.c_str(), rename_to.c_str());
     maybe_inject_failure();
@@ -844,7 +863,7 @@ int LFNIndex::lfn_unlink(const vector<string> &path,
 
 int LFNIndex::lfn_translate(const vector<string> &path,
 			    const string &short_name,
-			    hobject_t *out)
+			    ghobject_t *out)
 {
   if (!lfn_is_hashed_filename(short_name)) {
     return lfn_parse_object_name(short_name, out);
@@ -877,7 +896,7 @@ bool LFNIndex::lfn_is_subdir(const string &name, string *demangled)
   return 0;
 }
 
-static int parse_object(const char *s, hobject_t& o)
+static int parse_object(const char *s, ghobject_t& o)
 {
   const char *hash = s + strlen(s) - 1;
   while (*hash != '_' &&
@@ -913,28 +932,28 @@ static int parse_object(const char *s, hobject_t& o)
       i++;
     }
     *t = 0;
-    o.oid.name = string(buf, t-buf);
+    o.hobj.oid.name = string(buf, t-buf);
     if (strncmp(bar+1, "head", 4) == 0)
-      o.snap = CEPH_NOSNAP;
+      o.hobj.snap = CEPH_NOSNAP;
     else if (strncmp(bar+1, "snapdir", 7) == 0)
-      o.snap = CEPH_SNAPDIR;
+      o.hobj.snap = CEPH_SNAPDIR;
     else 
-      o.snap = strtoull(bar+1, NULL, 16);
-    sscanf(hash, "_%X", &o.hash);
+      o.hobj.snap = strtoull(bar+1, NULL, 16);
+    sscanf(hash, "_%X", &o.hobj.hash);
 
     return 1;
   }
   return 0;
 }
 
-bool LFNIndex::lfn_parse_object_name_keyless(const string &long_name, hobject_t *out)
+bool LFNIndex::lfn_parse_object_name_keyless(const string &long_name, ghobject_t *out)
 {
   bool r = parse_object(long_name.c_str(), *out);
   int64_t pool = -1;
   pg_t pg;
   if (coll().is_pg_prefix(pg))
     pool = (int64_t)pg.pool();
-  out->pool = pool;
+  out->hobj.pool = pool;
   if (!r) return r;
   string temp = lfn_generate_object_name(*out);
   return r;
@@ -965,7 +984,7 @@ static bool append_unescaped(string::const_iterator begin,
 }
 
 bool LFNIndex::lfn_parse_object_name_poolless(const string &long_name,
-					      hobject_t *out)
+					      ghobject_t *out)
 {
   string name;
   string key;
@@ -1027,12 +1046,12 @@ bool LFNIndex::lfn_parse_object_name_poolless(const string &long_name,
   pg_t pg;
   if (coll().is_pg_prefix(pg))
     pool = (int64_t)pg.pool();
-  (*out) = hobject_t(name, key, snap, hash, pool, "");
+  (*out) = ghobject_t(hobject_t(name, key, snap, hash, pool, ""));
   return true;
 }
 
 
-bool LFNIndex::lfn_parse_object_name(const string &long_name, hobject_t *out)
+bool LFNIndex::lfn_parse_object_name(const string &long_name, ghobject_t *out)
 {
   string name;
   string key;
@@ -1040,6 +1059,8 @@ bool LFNIndex::lfn_parse_object_name(const string &long_name, hobject_t *out)
   uint32_t hash;
   snapid_t snap;
   uint64_t pool;
+  gen_t generation = ghobject_t::NO_GEN;
+  shard_t shard_id = ghobject_t::NO_SHARD;
 
   if (index_version == HASH_INDEX_TAG)
     return lfn_parse_object_name_keyless(long_name, out);
@@ -1097,10 +1118,28 @@ bool LFNIndex::lfn_parse_object_name(const string &long_name, hobject_t *out)
 
   current = ++end;
   for ( ; end != long_name.end() && *end != '_'; ++end) ;
-  if (end != long_name.end())
-    return false;
   string pstring(current, end);
 
+  // Optional generation/shard_id
+  string genstring, shardstring;
+  if (end != long_name.end()) {
+    current = ++end;
+    for ( ; end != long_name.end() && *end != '_'; ++end) ;
+    if (end == long_name.end())
+      return false;
+    genstring = string(current, end);
+
+    generation = (gen_t)strtoull(genstring.c_str(), NULL, 16);
+
+    current = ++end;
+    for ( ; end != long_name.end() && *end != '_'; ++end) ;
+    if (end != long_name.end())
+      return false;
+    shardstring = string(current, end);
+
+    shard_id = (shard_t)strtoul(shardstring.c_str(), NULL, 16);
+  }
+
   if (snap_str == "head")
     snap = CEPH_NOSNAP;
   else if (snap_str == "snapdir")
@@ -1114,7 +1153,7 @@ bool LFNIndex::lfn_parse_object_name(const string &long_name, hobject_t *out)
   else
     pool = strtoull(pstring.c_str(), NULL, 16);
 
-  (*out) = hobject_t(name, key, snap, hash, (int64_t)pool, ns);
+  (*out) = ghobject_t(hobject_t(name, key, snap, hash, (int64_t)pool, ns), generation, shard_id);
   return true;
 }
 
@@ -1186,9 +1225,9 @@ void LFNIndex::build_filename(const char *old_filename, int i, char *filename, i
   }
 }
 
-string LFNIndex::lfn_get_short_name(const hobject_t &hoid, int i)
+string LFNIndex::lfn_get_short_name(const ghobject_t &oid, int i)
 {
-  string long_name = lfn_generate_object_name(hoid);
+  string long_name = lfn_generate_object_name(oid);
   assert(lfn_must_hash(long_name));
   char buf[FILENAME_SHORT_LEN + 4];
   build_filename(long_name.c_str(), i, buf, sizeof(buf));
@@ -1228,7 +1267,7 @@ string LFNIndex::demangle_path_component(const string &component)
 }
 
 int LFNIndex::decompose_full_path(const char *in, vector<string> *out,
-				  hobject_t *hoid, string *shortname)
+				  ghobject_t *oid, string *shortname)
 {
   const char *beginning = in + get_base_path().size();
   const char *end = beginning;
@@ -1244,8 +1283,8 @@ int LFNIndex::decompose_full_path(const char *in, vector<string> *out,
     }
   }
   *shortname = string(beginning, end - beginning);
-  if (hoid) {
-    int r = lfn_translate(*out, *shortname, hoid);
+  if (oid) {
+    int r = lfn_translate(*out, *shortname, oid);
     if (r < 0)
       return r;
   }
diff --git a/src/os/LFNIndex.h b/src/os/LFNIndex.h
index b73ff4db268..f436446bf0f 100644
--- a/src/os/LFNIndex.h
+++ b/src/os/LFNIndex.h
@@ -165,35 +165,35 @@ public:
 
   /// @see CollectionIndex
   int created(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     const char *path
     );
 
   /// @see CollectionIndex
   int unlink(
-    const hobject_t &hoid
+    const ghobject_t &oid
     );
 
   /// @see CollectionIndex
   int lookup(
-    const hobject_t &hoid,
+    const ghobject_t &oid,
     IndexedPath *path,
     int *exist
     );
 
   /// @see CollectionIndex
   int collection_list(
-    vector<hobject_t> *ls
+    vector<ghobject_t> *ls
     );
 
   /// @see CollectionIndex
   int collection_list_partial(
-    const hobject_t &start,
+    const ghobject_t &start,
     int min_count,
     int max_count,
     snapid_t seq,
-    vector<hobject_t> *ls,
-    hobject_t *next
+    vector<ghobject_t> *ls,
+    ghobject_t *next
     );
 
   virtual int _split(
@@ -221,20 +221,20 @@ protected:
   /// Will be called upon object creation
   virtual int _created(
     const vector<string> &path, ///< [in] Path to subdir.
-    const hobject_t &hoid,      ///< [in] Object created.
+    const ghobject_t &oid,      ///< [in] Object created.
     const string &mangled_name  ///< [in] Mangled filename.
     ) = 0;
 
   /// Will be called to remove an object
   virtual int _remove(
     const vector<string> &path,     ///< [in] Path to subdir.
-    const hobject_t &hoid,          ///< [in] Object to remove.
+    const ghobject_t &oid,          ///< [in] Object to remove.
     const string &mangled_name	    ///< [in] Mangled filename.
     ) = 0;
 
-  /// Return the path and mangled_name for hoid.
+  /// Return the path and mangled_name for oid.
   virtual int _lookup(
-    const hobject_t &hoid,///< [in] Object for lookup.
+    const ghobject_t &oid,///< [in] Object for lookup.
     vector<string> *path, ///< [out] Path to the object.
     string *mangled_name, ///< [out] Mangled filename.
     int *exists		  ///< [out] True if the object exists.
@@ -252,17 +252,17 @@ protected:
    */
   /// List contents of collection.
   virtual int _collection_list(
-    vector<hobject_t> *ls ///< [out] Listed objects.
+    vector<ghobject_t> *ls ///< [out] Listed objects.
     ) = 0;
 
   /// @see CollectionIndex
   virtual int _collection_list_partial(
-    const hobject_t &start,
+    const ghobject_t &start,
     int min_count,
     int max_count,
     snapid_t seq,
-    vector<hobject_t> *ls,
-    hobject_t *next
+    vector<ghobject_t> *ls,
+    ghobject_t *next
     ) = 0;
 
 protected:
@@ -278,8 +278,8 @@ protected:
   int link_object(
     const vector<string> &from,   ///< [in] Source subdirectory.
     const vector<string> &to,     ///< [in] Dest subdirectory.
-    const hobject_t &hoid,        ///< [in] Object to move.
-    const string &from_short_name ///< [in] Mangled filename of hoid.
+    const ghobject_t &oid,        ///< [in] Object to move.
+    const string &from_short_name ///< [in] Mangled filename of oid.
     ); ///< @return Error Code, 0 on success
 
   /**
@@ -296,8 +296,8 @@ protected:
    */
   int remove_objects(
     const vector<string> &dir,             
-    const map<string, hobject_t> &to_remove,
-    map<string, hobject_t> *remaining
+    const map<string, ghobject_t> &to_remove,
+    map<string, ghobject_t> *remaining
     );
 	
 
@@ -322,11 +322,11 @@ protected:
    */
   int remove_object(
     const vector<string> &from,  ///< [in] Directory from which to remove.
-    const hobject_t &to_remove   ///< [in] Object to remove.
+    const ghobject_t &to_remove   ///< [in] Object to remove.
     );
 
   /**
-   * Gets the filename corresponding to hoid in from.
+   * Gets the filename corresponding to oid in from.
    * 
    * The filename may differ between subdirectories.  Furthermore,
    * file creations ore removals in from may invalidate the name.
@@ -334,7 +334,7 @@ protected:
    */
   int get_mangled_name(
     const vector<string> &from, ///< [in] Subdirectory
-    const hobject_t &hoid,	///< [in] Object 
+    const ghobject_t &oid,	///< [in] Object
     string *mangled_name,	///< [out] Filename
     int *exists			///< [out] 1 if the file exists, else 0
     );
@@ -352,7 +352,7 @@ protected:
     LFNIndex &from,             ///< [in] from index
     LFNIndex &dest,             ///< [in] to index
     const vector<string> &path, ///< [in] path to split
-    const pair<string, hobject_t> &obj ///< [in] obj to move
+    const pair<string, ghobject_t> &obj ///< [in] obj to move
     );
 
   /**
@@ -369,7 +369,7 @@ protected:
     const vector<string> &to_list,
     int max_objects,
     long *handle,
-    map<string, hobject_t> *out
+    map<string, ghobject_t> *out
     );
 
   /// Lists subdirectories.
@@ -425,43 +425,43 @@ private:
   }
 
   /**
-   * Gets the filename corresponsing to hoid in path.
+   * Gets the filename corresponsing to oid in path.
    *
-   * @param [in] path Path in which to get filename for hoid.
-   * @param [in] hoid Object for which to get filename.
-   * @param [out] mangled_name Filename for hoid, pass NULL if not needed.
-   * @param [out] full_path Fullpath for hoid, pass NULL if not needed.
+   * @param [in] path Path in which to get filename for oid.
+   * @param [in] oid Object for which to get filename.
+   * @param [out] mangled_name Filename for oid, pass NULL if not needed.
+   * @param [out] full_path Fullpath for oid, pass NULL if not needed.
    * @param [out] exists 1 if the file exists, 0 otherwise, pass NULL if 
    * not needed
    * @return Error Code, 0 on success.
    */
   int lfn_get_name(
     const vector<string> &path,
-    const hobject_t &hoid, 
+    const ghobject_t &oid,
     string *mangled_name,
     string *full_path,
     int *exists
     );
 
-  /// Adjusts path contents when hoid is created at name mangled_name.
+  /// Adjusts path contents when oid is created at name mangled_name.
   int lfn_created(
     const vector<string> &path, ///< [in] Path to adjust.
-    const hobject_t &hoid,	///< [in] Object created. 
+    const ghobject_t &oid,	///< [in] Object created.
     const string &mangled_name  ///< [in] Filename of created object.
     );
 
-  /// Removes hoid from path while adjusting path contents
+  /// Removes oid from path while adjusting path contents
   int lfn_unlink(
-    const vector<string> &path, ///< [in] Path containing hoid.
-    const hobject_t &hoid,	///< [in] Object to remove.
+    const vector<string> &path, ///< [in] Path containing oid.
+    const ghobject_t &oid,	///< [in] Object to remove.
     const string &mangled_name	///< [in] Filename of object to remove.
     );
 
-  ///Transate a file into and hobject_t.
+  ///Transate a file into and ghobject_t.
   int lfn_translate(
     const vector<string> &path, ///< [in] Path containing the file.
     const string &short_name,	///< [in] Filename to translate. 
-    hobject_t *out		///< [out] Object found.
+    ghobject_t *out		///< [out] Object found.
     ); ///< @return Negative error code on error, 0 if not an object, 1 else
 
   /* manglers/demanglers */
@@ -478,35 +478,35 @@ private:
 
   /// Generate object name
   string lfn_generate_object_name_keyless(
-    const hobject_t &hoid ///< [in] Object for which to generate.
+    const ghobject_t &oid ///< [in] Object for which to generate.
     ); ///< @return Generated object name.
 
   /// Generate object name
   string lfn_generate_object_name_poolless(
-    const hobject_t &hoid ///< [in] Object for which to generate.
+    const ghobject_t &oid ///< [in] Object for which to generate.
     ); ///< @return Generated object name.
 
   /// Generate object name
   string lfn_generate_object_name(
-    const hobject_t &hoid ///< [in] Object for which to generate.
+    const ghobject_t &oid ///< [in] Object for which to generate.
     ); ///< @return Generated object name.
 
   /// Parse object name
   bool lfn_parse_object_name_keyless(
     const string &long_name, ///< [in] Name to parse
-    hobject_t *out	     ///< [out] Resulting Object
+    ghobject_t *out	     ///< [out] Resulting Object
     ); ///< @return True if successfull, False otherwise.
 
   /// Parse object name
   bool lfn_parse_object_name_poolless(
     const string &long_name, ///< [in] Name to parse
-    hobject_t *out	     ///< [out] Resulting Object
+    ghobject_t *out	     ///< [out] Resulting Object
     ); ///< @return True if successfull, False otherwise.
 
   /// Parse object name
   bool lfn_parse_object_name(
     const string &long_name, ///< [in] Name to parse
-    hobject_t *out	     ///< [out] Resulting Object
+    ghobject_t *out	     ///< [out] Resulting Object
     ); ///< @return True if successfull, False otherwise.
 
   /// Checks whether short_name is a hashed filename.
@@ -521,7 +521,7 @@ private:
 
   /// Generate hashed name.
   string lfn_get_short_name(
-    const hobject_t &hoid, ///< [in] Object for which to generate.
+    const ghobject_t &oid, ///< [in] Object for which to generate.
     int i		   ///< [in] Index of hashed name to generate.
     ); ///< @return Hashed filename.
 
@@ -554,7 +554,7 @@ private:
   int decompose_full_path(
     const char *in,      ///< [in] Full path to object.
     vector<string> *out, ///< [out] Path to object at in.
-    hobject_t *hoid,	 ///< [out] Object at in.
+    ghobject_t *oid,	 ///< [out] Object at in.
     string *shortname	 ///< [out] Filename of object at in.
     ); ///< @return Error Code, 0 on success.
 
diff --git a/src/os/ObjectMap.h b/src/os/ObjectMap.h
index 5cc1e495de1..7717aac7437 100644
--- a/src/os/ObjectMap.h
+++ b/src/os/ObjectMap.h
@@ -30,102 +30,102 @@ class ObjectMap {
 public:
   /// Set keys and values from specified map
   virtual int set_keys(
-    const hobject_t &hoid,              ///< [in] object containing map
+    const ghobject_t &oid,              ///< [in] object containing map
     const map<string, bufferlist> &set,  ///< [in] key to value map to set
     const SequencerPosition *spos=0     ///< [in] sequencer position
     ) = 0;
 
   /// Set header
   virtual int set_header(
-    const hobject_t &hoid,              ///< [in] object containing map
+    const ghobject_t &oid,              ///< [in] object containing map
     const bufferlist &bl,               ///< [in] header to set
     const SequencerPosition *spos=0     ///< [in] sequencer position
     ) = 0;
 
   /// Retrieve header
   virtual int get_header(
-    const hobject_t &hoid,              ///< [in] object containing map
+    const ghobject_t &oid,              ///< [in] object containing map
     bufferlist *bl                      ///< [out] header to set
     ) = 0;
 
-  /// Clear all map keys and values from hoid
+  /// Clear all map keys and values from oid
   virtual int clear(
-    const hobject_t &hoid,             ///< [in] object containing map
+    const ghobject_t &oid,             ///< [in] object containing map
     const SequencerPosition *spos=0     ///< [in] sequencer position
     ) = 0;
 
-  /// Clear all map keys and values from hoid
+  /// Clear all map keys and values from oid
   virtual int rm_keys(
-    const hobject_t &hoid,              ///< [in] object containing map
+    const ghobject_t &oid,              ///< [in] object containing map
     const set<string> &to_clear,        ///< [in] Keys to clear
     const SequencerPosition *spos=0     ///< [in] sequencer position
     ) = 0;
 
   /// Get all keys and values
   virtual int get(
-    const hobject_t &hoid,             ///< [in] object containing map
+    const ghobject_t &oid,             ///< [in] object containing map
     bufferlist *header,                ///< [out] Returned Header
     map<string, bufferlist> *out       ///< [out] Returned keys and values
     ) = 0;
 
   /// Get values for supplied keys
   virtual int get_keys(
-    const hobject_t &hoid,             ///< [in] object containing map
-    set<string> *keys                  ///< [out] Keys defined on hoid
+    const ghobject_t &oid,             ///< [in] object containing map
+    set<string> *keys                  ///< [out] Keys defined on oid
     ) = 0;
 
   /// Get values for supplied keys
   virtual int get_values(
-    const hobject_t &hoid,             ///< [in] object containing map
+    const ghobject_t &oid,             ///< [in] object containing map
     const set<string> &keys,           ///< [in] Keys to get
     map<string, bufferlist> *out       ///< [out] Returned keys and values
     ) = 0;
 
   /// Check key existence
   virtual int check_keys(
-    const hobject_t &hoid,             ///< [in] object containing map
+    const ghobject_t &oid,             ///< [in] object containing map
     const set<string> &keys,           ///< [in] Keys to check
-    set<string> *out                   ///< [out] Subset of keys defined on hoid
+    set<string> *out                   ///< [out] Subset of keys defined on oid
     ) = 0;
 
   /// Get xattrs
   virtual int get_xattrs(
-    const hobject_t &hoid,             ///< [in] object
+    const ghobject_t &oid,             ///< [in] object
     const set<string> &to_get,         ///< [in] keys to get
     map<string, bufferlist> *out       ///< [out] subset of attrs/vals defined
     ) = 0;
 
   /// Get all xattrs
   virtual int get_all_xattrs(
-    const hobject_t &hoid,             ///< [in] object
+    const ghobject_t &oid,             ///< [in] object
     set<string> *out       ///< [out] attrs and values
     ) = 0;
 
   /// set xattrs in to_set
   virtual int set_xattrs(
-    const hobject_t &hoid,                ///< [in] object
+    const ghobject_t &oid,                ///< [in] object
     const map<string, bufferlist> &to_set,///< [in] attrs/values to set
     const SequencerPosition *spos=0     ///< [in] sequencer position
     ) = 0;
 
   /// remove xattrs in to_remove
   virtual int remove_xattrs(
-    const hobject_t &hoid,               ///< [in] object
+    const ghobject_t &oid,               ///< [in] object
     const set<string> &to_remove,        ///< [in] attrs to remove
     const SequencerPosition *spos=0     ///< [in] sequencer position
     ) = 0;
 
 
-  /// Clone keys efficiently from hoid map to target map
+  /// Clone keys efficiently from oid map to target map
   virtual int clone(
-    const hobject_t &hoid,             ///< [in] object containing map
-    const hobject_t &target,           ///< [in] target of clone
+    const ghobject_t &oid,             ///< [in] object containing map
+    const ghobject_t &target,           ///< [in] target of clone
     const SequencerPosition *spos=0     ///< [in] sequencer position
     ) { return 0; }
 
   /// Ensure all previous writes are durable
   virtual int sync(
-    const hobject_t *hoid=0,          ///< [in] object
+    const ghobject_t *oid=0,          ///< [in] object
     const SequencerPosition *spos=0   ///< [in] Sequencer
     ) { return 0; }
 
@@ -144,7 +144,7 @@ public:
     virtual ~ObjectMapIteratorImpl() {}
   };
   typedef std::tr1::shared_ptr<ObjectMapIteratorImpl> ObjectMapIterator;
-  virtual ObjectMapIterator get_iterator(const hobject_t &hoid) {
+  virtual ObjectMapIterator get_iterator(const ghobject_t &oid) {
     return ObjectMapIterator();
   }
 
diff --git a/src/os/ObjectStore.cc b/src/os/ObjectStore.cc
index 9d8b989225b..97c858b6773 100644
--- a/src/os/ObjectStore.cc
+++ b/src/os/ObjectStore.cc
@@ -77,7 +77,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_TOUCH:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	f->dump_string("op_name", "touch");
 	f->dump_stream("collection") << cid;
 	f->dump_stream("oid") << oid;
@@ -87,7 +87,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_WRITE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	uint64_t off = i.get_length();
 	uint64_t len = i.get_length();
 	bufferlist bl;
@@ -104,7 +104,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_ZERO:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	uint64_t off = i.get_length();
 	uint64_t len = i.get_length();
 	f->dump_string("op_name", "zero");
@@ -118,7 +118,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_TRIMCACHE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	uint64_t off = i.get_length();
 	uint64_t len = i.get_length();
 	f->dump_string("op_name", "trim_cache");
@@ -132,7 +132,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_TRUNCATE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	uint64_t off = i.get_length();
 	f->dump_string("op_name", "truncate");
 	f->dump_stream("collection") << cid;
@@ -144,7 +144,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_REMOVE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	f->dump_string("op_name", "remove");
 	f->dump_stream("collection") << cid;
 	f->dump_stream("oid") << oid;
@@ -154,7 +154,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_SETATTR:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	string name = i.get_attrname();
 	bufferlist bl;
 	i.get_bl(bl);
@@ -169,7 +169,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_SETATTRS:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	map<string, bufferptr> aset;
 	i.get_attrset(aset);
 	f->dump_string("op_name", "setattrs");
@@ -187,7 +187,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_RMATTR:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	string name = i.get_attrname();
 	f->dump_string("op_name", "rmattr");
 	f->dump_stream("collection") << cid;
@@ -199,7 +199,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_RMATTRS:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	f->dump_string("op_name", "rmattrs");
 	f->dump_stream("collection") << cid;
 	f->dump_stream("oid") << oid;
@@ -209,8 +209,8 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_CLONE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
-	hobject_t noid = i.get_oid();
+	ghobject_t oid = i.get_oid();
+	ghobject_t noid = i.get_oid();
 	f->dump_string("op_name", "clone");
 	f->dump_stream("collection") << cid;
 	f->dump_stream("src_oid") << oid;
@@ -221,8 +221,8 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_CLONERANGE:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
-	hobject_t noid = i.get_oid();
+	ghobject_t oid = i.get_oid();
+	ghobject_t noid = i.get_oid();
  	uint64_t off = i.get_length();
 	uint64_t len = i.get_length();
 	f->dump_string("op_name", "clonerange");
@@ -237,8 +237,8 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_CLONERANGE2:
       {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
-	hobject_t noid = i.get_oid();
+	ghobject_t oid = i.get_oid();
+	ghobject_t noid = i.get_oid();
  	uint64_t srcoff = i.get_length();
 	uint64_t len = i.get_length();
  	uint64_t dstoff = i.get_length();
@@ -272,7 +272,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
       {
 	coll_t ocid = i.get_cid();
 	coll_t ncid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	f->dump_string("op_name", "collection_add");
 	f->dump_stream("src_collection") << ocid;
 	f->dump_stream("dst_collection") << ncid;
@@ -283,7 +283,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_COLL_REMOVE:
        {
 	coll_t cid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	f->dump_string("op_name", "collection_remove");
 	f->dump_stream("collection") << cid;
 	f->dump_stream("oid") << oid;
@@ -294,7 +294,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
        {
 	coll_t ocid = i.get_cid();
 	coll_t ncid = i.get_cid();
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	f->open_object_section("collection_move");
 	f->dump_stream("src_collection") << ocid;
 	f->dump_stream("dst_collection") << ncid;
@@ -344,7 +344,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_OMAP_CLEAR:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	f->dump_string("op_name", "omap_clear");
 	f->dump_stream("collection") << cid;
 	f->dump_stream("oid") << oid;
@@ -354,7 +354,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_OMAP_SETKEYS:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	map<string, bufferlist> aset;
 	i.get_attrset(aset);
 	f->dump_string("op_name", "omap_setkeys");
@@ -372,7 +372,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_OMAP_RMKEYS:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	set<string> keys;
 	i.get_keyset(keys);
 	f->dump_string("op_name", "omap_rmkeys");
@@ -384,7 +384,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_OMAP_SETHEADER:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	bufferlist bl;
 	i.get_bl(bl);
 	f->dump_string("op_name", "omap_setheader");
@@ -425,7 +425,7 @@ void ObjectStore::Transaction::dump(ceph::Formatter *f)
     case Transaction::OP_OMAP_RMKEYRANGE:
       {
 	coll_t cid(i.get_cid());
-	hobject_t oid = i.get_oid();
+	ghobject_t oid = i.get_oid();
 	string first, last;
 	first = i.get_key();
 	last = i.get_key();
@@ -460,9 +460,9 @@ void ObjectStore::Transaction::generate_test_instances(list<ObjectStore::Transac
   t = new Transaction;
   coll_t c("foocoll");
   coll_t c2("foocoll2");
-  hobject_t o1("obj", "", 123, 456, -1, "");
-  hobject_t o2("obj2", "", 123, 456, -1, "");
-  hobject_t o3("obj3", "", 123, 456, -1, "");
+  ghobject_t o1(hobject_t("obj", "", 123, 456, -1, ""));
+  ghobject_t o2(hobject_t("obj2", "", 123, 456, -1, ""));
+  ghobject_t o3(hobject_t("obj3", "", 123, 456, -1, ""));
   t->touch(c, o1);
   bufferlist bl;
   bl.append("some data");
diff --git a/src/os/ObjectStore.h b/src/os/ObjectStore.h
index 2602b19a11e..aea12c2aa2c 100644
--- a/src/os/ObjectStore.h
+++ b/src/os/ObjectStore.h
@@ -340,21 +340,23 @@ public:
       void get_bl(bufferlist& bl) {
 	::decode(bl, p);
       }
-      hobject_t get_oid() {
-	hobject_t hoid;
+      ghobject_t get_oid() {
+	ghobject_t oid;
 	if (sobject_encoding) {
 	  sobject_t soid;
 	  ::decode(soid, p);
-	  hoid.snap = soid.snap;
-	  hoid.oid = soid.oid;
+	  oid.hobj.snap = soid.snap;
+	  oid.hobj.oid = soid.oid;
+	  oid.generation = ghobject_t::NO_GEN;
+	  oid.shard_id = ghobject_t::NO_SHARD;
 	} else {
-	  ::decode(hoid, p);
+	  ::decode(oid, p);
 	  if (use_pool_override && pool_override != -1 &&
-	      hoid.pool == -1) {
-	    hoid.pool = pool_override;
+	      oid.hobj.pool == -1) {
+	    oid.hobj.pool = pool_override;
 	  }
 	}
-	return hoid;
+	return oid;
       }
       coll_t get_cid() {
 	coll_t c;
@@ -408,14 +410,14 @@ public:
       ::encode(op, tbl);
       ops++;
     }
-    void touch(coll_t cid, const hobject_t& oid) {
+    void touch(coll_t cid, const ghobject_t& oid) {
       __u32 op = OP_TOUCH;
       ::encode(op, tbl);
       ::encode(cid, tbl);
       ::encode(oid, tbl);
       ops++;
     }
-    void write(coll_t cid, const hobject_t& oid, uint64_t off, uint64_t len, const bufferlist& data) {
+    void write(coll_t cid, const ghobject_t& oid, uint64_t off, uint64_t len, const bufferlist& data) {
       __u32 op = OP_WRITE;
       ::encode(op, tbl);
       ::encode(cid, tbl);
@@ -431,7 +433,7 @@ public:
       ::encode(data, tbl);
       ops++;
     }
-    void zero(coll_t cid, const hobject_t& oid, uint64_t off, uint64_t len) {
+    void zero(coll_t cid, const ghobject_t& oid, uint64_t off, uint64_t len) {
       __u32 op = OP_ZERO;
       ::encode(op, tbl);
       ::encode(cid, tbl);
@@ -440,7 +442,7 @@ public:
       ::encode(len, tbl);
       ops++;
     }
-    void truncate(coll_t cid, const hobject_t& oid, uint64_t off) {
+    void truncate(coll_t cid, const ghobject_t& oid, uint64_t off) {
       __u32 op = OP_TRUNCATE;
       ::encode(op, tbl);
       ::encode(cid, tbl);
@@ -448,18 +450,18 @@ public:
       ::encode(off, tbl);
       ops++;
     }
-    void remove(coll_t cid, const hobject_t& oid) {
+    void remove(coll_t cid, const ghobject_t& oid) {
       __u32 op = OP_REMOVE;
       ::encode(op, tbl);
       ::encode(cid, tbl);
       ::encode(oid, tbl);
       ops++;
     }
-    void setattr(coll_t cid, const hobject_t& oid, const char* name, bufferlist& val) {
+    void setattr(coll_t cid, const ghobject_t& oid, const char* name, bufferlist& val) {
       string n(name);
       setattr(cid, oid, n, val);
     }
-    void setattr(coll_t cid, const hobject_t& oid, const string& s, bufferlist& val) {
+    void setattr(coll_t cid, const ghobject_t& oid, const string& s, bufferlist& val) {
       __u32 op = OP_SETATTR;
       ::encode(op, tbl);
       ::encode(cid, tbl);
@@ -468,7 +470,7 @@ public:
       ::encode(val, tbl);
       ops++;
     }
-    void setattrs(coll_t cid, const hobject_t& oid, map<string,bufferptr>& attrset) {
+    void setattrs(coll_t cid, const ghobject_t& oid, map<string,bufferptr>& attrset) {
       __u32 op = OP_SETATTRS;
       ::encode(op, tbl);
       ::encode(cid, tbl);
@@ -484,11 +486,11 @@ public:
       ::encode(attrset, tbl);
       ops++;
     }
-    void rmattr(coll_t cid, const hobject_t& oid, const char *name) {
+    void rmattr(coll_t cid, const ghobject_t& oid, const char *name) {
       string n(name);
       rmattr(cid, oid, n);
     }
-    void rmattr(coll_t cid, const hobject_t& oid, const string& s) {
+    void rmattr(coll_t cid, const ghobject_t& oid, const string& s) {
       __u32 op = OP_RMATTR;
       ::encode(op, tbl);
       ::encode(cid, tbl);
@@ -496,14 +498,14 @@ public:
       ::encode(s, tbl);
       ops++;
     }
-    void rmattrs(coll_t cid, const hobject_t& oid) {
+    void rmattrs(coll_t cid, const ghobject_t& oid) {
       __u32 op = OP_RMATTR;
       ::encode(op, tbl);
       ::encode(cid, tbl);
       ::encode(oid, tbl);
       ops++;
     }
-    void clone(coll_t cid, const hobject_t& oid, hobject_t noid) {
+    void clone(coll_t cid, const ghobject_t& oid, ghobject_t noid) {
       __u32 op = OP_CLONE;
       ::encode(op, tbl);
       ::encode(cid, tbl);
@@ -511,7 +513,7 @@ public:
       ::encode(noid, tbl);
       ops++;
     }
-    void clone_range(coll_t cid, const hobject_t& oid, hobject_t noid,
+    void clone_range(coll_t cid, const ghobject_t& oid, ghobject_t noid,
 		     uint64_t srcoff, uint64_t srclen, uint64_t dstoff) {
       __u32 op = OP_CLONERANGE2;
       ::encode(op, tbl);
@@ -535,7 +537,7 @@ public:
       ::encode(cid, tbl);
       ops++;
     }
-    void collection_add(coll_t cid, coll_t ocid, const hobject_t& oid) {
+    void collection_add(coll_t cid, coll_t ocid, const ghobject_t& oid) {
       __u32 op = OP_COLL_ADD;
       ::encode(op, tbl);
       ::encode(cid, tbl);
@@ -543,20 +545,20 @@ public:
       ::encode(oid, tbl);
       ops++;
     }
-    void collection_remove(coll_t cid, const hobject_t& oid) {
+    void collection_remove(coll_t cid, const ghobject_t& oid) {
       __u32 op = OP_COLL_REMOVE;
       ::encode(op, tbl);
       ::encode(cid, tbl);
       ::encode(oid, tbl);
       ops++;
     }
-    void collection_move(coll_t cid, coll_t oldcid, const hobject_t& oid) {
+    void collection_move(coll_t cid, coll_t oldcid, const ghobject_t& oid) {
       collection_add(cid, oldcid, oid);
       collection_remove(oldcid, oid);
       return;
     }
-    void collection_move_rename(coll_t oldcid, const hobject_t& oldoid,
-				coll_t cid, const hobject_t& oid) {
+    void collection_move_rename(coll_t oldcid, const ghobject_t& oldoid,
+				coll_t cid, const ghobject_t& oid) {
       __u32 op = OP_COLL_MOVE_RENAME;
       ::encode(op, tbl);
       ::encode(oldcid, tbl);
@@ -611,55 +613,55 @@ public:
       ops++;
     }
 
-    /// Remove omap from hoid
+    /// Remove omap from oid
     void omap_clear(
-      coll_t cid,           ///< [in] Collection containing hoid
-      const hobject_t &hoid ///< [in] Object from which to remove omap
+      coll_t cid,           ///< [in] Collection containing oid
+      const ghobject_t &oid  ///< [in] Object from which to remove omap
       ) {
       __u32 op = OP_OMAP_CLEAR;
       ::encode(op, tbl);
       ::encode(cid, tbl);
-      ::encode(hoid, tbl);
+      ::encode(oid, tbl);
       ops++;
     }
-    /// Set keys on hoid omap.  Replaces duplicate keys.
+    /// Set keys on oid omap.  Replaces duplicate keys.
     void omap_setkeys(
-      coll_t cid,                           ///< [in] Collection containing hoid
-      const hobject_t &hoid,                ///< [in] Object to update
+      coll_t cid,                           ///< [in] Collection containing oid
+      const ghobject_t &oid,                ///< [in] Object to update
       const map<string, bufferlist> &attrset ///< [in] Replacement keys and values
       ) {
       __u32 op = OP_OMAP_SETKEYS;
       ::encode(op, tbl);
       ::encode(cid, tbl);
-      ::encode(hoid, tbl);
+      ::encode(oid, tbl);
       ::encode(attrset, tbl);
       ops++;
     }
-    /// Remove keys from hoid omap
+    /// Remove keys from oid omap
     void omap_rmkeys(
-      coll_t cid,             ///< [in] Collection containing hoid
-      const hobject_t &hoid,  ///< [in] Object from which to remove the omap
+      coll_t cid,             ///< [in] Collection containing oid
+      const ghobject_t &oid,  ///< [in] Object from which to remove the omap
       const set<string> &keys ///< [in] Keys to clear
       ) {
       __u32 op = OP_OMAP_RMKEYS;
       ::encode(op, tbl);
       ::encode(cid, tbl);
-      ::encode(hoid, tbl);
+      ::encode(oid, tbl);
       ::encode(keys, tbl);
       ops++;
     }
 
-    /// Remove key range from hoid omap
+    /// Remove key range from oid omap
     void omap_rmkeyrange(
-      coll_t cid,             ///< [in] Collection containing hoid
-      const hobject_t &hoid,  ///< [in] Object from which to remove the omap
+      coll_t cid,             ///< [in] Collection containing oid
+      const ghobject_t &oid,  ///< [in] Object from which to remove the omap
       const string& first,    ///< [in] first key in range
       const string& last      ///< [in] first key past range
       ) {
       __u32 op = OP_OMAP_RMKEYRANGE;
       ::encode(op, tbl);
       ::encode(cid, tbl);
-      ::encode(hoid, tbl);
+      ::encode(oid, tbl);
       ::encode(first, tbl);
       ::encode(last, tbl);
       ops++;
@@ -667,14 +669,14 @@ public:
 
     /// Set omap header
     void omap_setheader(
-      coll_t cid,             ///< [in] Collection containing hoid
-      const hobject_t &hoid,  ///< [in] Object from which to remove the omap
+      coll_t cid,             ///< [in] Collection containing oid
+      const ghobject_t &oid,  ///< [in] Object from which to remove the omap
       const bufferlist &bl    ///< [in] Header value
       ) {
       __u32 op = OP_OMAP_SETHEADER;
       ::encode(op, tbl);
       ::encode(cid, tbl);
-      ::encode(hoid, tbl);
+      ::encode(oid, tbl);
       ::encode(bl, tbl);
       ops++;
     }
@@ -877,32 +879,32 @@ public:
   virtual int get_ideal_list_max() { return 64; }
 
   // objects
-  virtual bool exists(coll_t cid, const hobject_t& oid) = 0;                   // useful?
+  virtual bool exists(coll_t cid, const ghobject_t& oid) = 0;                   // useful?
   virtual int stat(
     coll_t cid,
-    const hobject_t& oid,
+    const ghobject_t& oid,
     struct stat *st,
     bool allow_eio = false) = 0; // struct stat?
 
   virtual int read(
     coll_t cid,
-    const hobject_t& oid,
+    const ghobject_t& oid,
     uint64_t offset,
     size_t len,
     bufferlist& bl,
     bool allow_eio = false) = 0;
 
-  virtual int fiemap(coll_t cid, const hobject_t& oid, uint64_t offset, size_t len, bufferlist& bl) = 0;
+  virtual int fiemap(coll_t cid, const ghobject_t& oid, uint64_t offset, size_t len, bufferlist& bl) = 0;
 
-  virtual int getattr(coll_t cid, const hobject_t& oid, const char *name, bufferptr& value) = 0;
-  int getattr(coll_t cid, const hobject_t& oid, const char *name, bufferlist& value) {
+  virtual int getattr(coll_t cid, const ghobject_t& oid, const char *name, bufferptr& value) = 0;
+  int getattr(coll_t cid, const ghobject_t& oid, const char *name, bufferlist& value) {
     bufferptr bp;
     int r = getattr(cid, oid, name, bp);
     if (bp.length())
       value.push_back(bp);
     return r;
   }
-  virtual int getattrs(coll_t cid, const hobject_t& oid, map<string,bufferptr>& aset, bool user_only = false) {return 0;};
+  virtual int getattrs(coll_t cid, const ghobject_t& oid, map<string,bufferptr>& aset, bool user_only = false) {return 0;};
 
    
   // collections
@@ -917,7 +919,7 @@ public:
   virtual int collection_getattr(coll_t cid, const char *name, bufferlist& bl) = 0;
   virtual int collection_getattrs(coll_t cid, map<string,bufferptr> &aset) = 0;
   virtual bool collection_empty(coll_t c) = 0;
-  virtual int collection_list(coll_t c, vector<hobject_t>& o) = 0;
+  virtual int collection_list(coll_t c, vector<ghobject_t>& o) = 0;
 
   /**
    * list partial contents of collection relative to a hash offset/position
@@ -931,9 +933,9 @@ public:
    * @param next [out] next item sorts >= this value
    * @return zero on success, or negative error
    */
-  virtual int collection_list_partial(coll_t c, hobject_t start,
+  virtual int collection_list_partial(coll_t c, ghobject_t start,
 				      int min, int max, snapid_t snap, 
-				      vector<hobject_t> *ls, hobject_t *next) = 0;
+				      vector<ghobject_t> *ls, ghobject_t *next) = 0;
 
   /**
    * list contents of a collection that fall in the range [start, end)
@@ -945,47 +947,47 @@ public:
    * @param ls [out] result
    * @return zero on success, or negative error
    */
-  virtual int collection_list_range(coll_t c, hobject_t start, hobject_t end,
-                                    snapid_t seq, vector<hobject_t> *ls) = 0;
+  virtual int collection_list_range(coll_t c, ghobject_t start, ghobject_t end,
+                                    snapid_t seq, vector<ghobject_t> *ls) = 0;
 
   /// OMAP
   /// Get omap contents
   virtual int omap_get(
-    coll_t c,                ///< [in] Collection containing hoid
-    const hobject_t &hoid,   ///< [in] Object containing omap
+    coll_t c,                ///< [in] Collection containing oid
+    const ghobject_t &oid,   ///< [in] Object containing omap
     bufferlist *header,      ///< [out] omap header
     map<string, bufferlist> *out /// < [out] Key to value map
     ) = 0;
 
   /// Get omap header
   virtual int omap_get_header(
-    coll_t c,                ///< [in] Collection containing hoid
-    const hobject_t &hoid,   ///< [in] Object containing omap
+    coll_t c,                ///< [in] Collection containing oid
+    const ghobject_t &oid,   ///< [in] Object containing omap
     bufferlist *header,      ///< [out] omap header
     bool allow_eio = false ///< [in] don't assert on eio
     ) = 0;
 
-  /// Get keys defined on hoid
+  /// Get keys defined on oid
   virtual int omap_get_keys(
-    coll_t c,              ///< [in] Collection containing hoid
-    const hobject_t &hoid, ///< [in] Object containing omap
-    set<string> *keys      ///< [out] Keys defined on hoid
+    coll_t c,              ///< [in] Collection containing oid
+    const ghobject_t &oid, ///< [in] Object containing omap
+    set<string> *keys      ///< [out] Keys defined on oid
     ) = 0;
 
   /// Get key values
   virtual int omap_get_values(
-    coll_t c,                    ///< [in] Collection containing hoid
-    const hobject_t &hoid,       ///< [in] Object containing omap
+    coll_t c,                    ///< [in] Collection containing oid
+    const ghobject_t &oid,       ///< [in] Object containing omap
     const set<string> &keys,     ///< [in] Keys to get
     map<string, bufferlist> *out ///< [out] Returned keys and values
     ) = 0;
 
-  /// Filters keys into out which are defined on hoid
+  /// Filters keys into out which are defined on oid
   virtual int omap_check_keys(
-    coll_t c,                ///< [in] Collection containing hoid
-    const hobject_t &hoid,   ///< [in] Object containing omap
+    coll_t c,                ///< [in] Collection containing oid
+    const ghobject_t &oid,   ///< [in] Object containing omap
     const set<string> &keys, ///< [in] Keys to check
-    set<string> *out         ///< [out] Subset of keys defined on hoid
+    set<string> *out         ///< [out] Subset of keys defined on oid
     ) = 0;
 
   /**
@@ -999,7 +1001,7 @@ public:
    */
   virtual ObjectMap::ObjectMapIterator get_omap_iterator(
     coll_t c,              ///< [in] collection
-    const hobject_t &hoid  ///< [in] object
+    const ghobject_t &oid  ///< [in] object
     ) = 0;
 
   virtual void sync(Context *onsync) {}
@@ -1015,8 +1017,8 @@ public:
   virtual uuid_d get_fsid() = 0;
 
   // DEBUG
-  virtual void inject_data_error(const hobject_t &oid) {}
-  virtual void inject_mdata_error(const hobject_t &oid) {}
+  virtual void inject_data_error(const ghobject_t &oid) {}
+  virtual void inject_mdata_error(const ghobject_t &oid) {}
 };
 
 
diff --git a/src/os/WBThrottle.cc b/src/os/WBThrottle.cc
index 8479b3c878d..e02c17677bb 100644
--- a/src/os/WBThrottle.cc
+++ b/src/os/WBThrottle.cc
@@ -116,7 +116,7 @@ void WBThrottle::handle_conf_change(const md_config_t *conf,
 }
 
 bool WBThrottle::get_next_should_flush(
-  boost::tuple<hobject_t, FDRef, PendingWB> *next)
+  boost::tuple<ghobject_t, FDRef, PendingWB> *next)
 {
   assert(lock.is_locked());
   assert(next);
@@ -128,9 +128,9 @@ bool WBThrottle::get_next_should_flush(
   if (stopping)
     return false;
   assert(!pending_wbs.empty());
-  hobject_t obj(pop_object());
+  ghobject_t obj(pop_object());
   
-  map<hobject_t, pair<PendingWB, FDRef> >::iterator i =
+  map<ghobject_t, pair<PendingWB, FDRef> >::iterator i =
     pending_wbs.find(obj);
   *next = boost::make_tuple(obj, i->second.second, i->second.first);
   pending_wbs.erase(i);
@@ -141,7 +141,7 @@ bool WBThrottle::get_next_should_flush(
 void *WBThrottle::entry()
 {
   Mutex::Locker l(lock);
-  boost::tuple<hobject_t, FDRef, PendingWB> wb;
+  boost::tuple<ghobject_t, FDRef, PendingWB> wb;
   while (get_next_should_flush(&wb)) {
     clearing = wb.get<0>();
     lock.Unlock();
@@ -149,24 +149,24 @@ void *WBThrottle::entry()
     if (wb.get<2>().nocache)
       posix_fadvise(**wb.get<1>(), 0, 0, POSIX_FADV_DONTNEED);
     lock.Lock();
-    clearing = hobject_t();
+    clearing = ghobject_t();
     cur_ios -= wb.get<2>().ios;
     logger->dec(l_wbthrottle_ios_dirtied, wb.get<2>().ios);
     cur_size -= wb.get<2>().size;
     logger->dec(l_wbthrottle_bytes_dirtied, wb.get<2>().size);
     logger->dec(l_wbthrottle_inodes_dirtied);
     cond.Signal();
-    wb = boost::tuple<hobject_t, FDRef, PendingWB>();
+    wb = boost::tuple<ghobject_t, FDRef, PendingWB>();
   }
   return 0;
 }
 
 void WBThrottle::queue_wb(
-  FDRef fd, const hobject_t &hoid, uint64_t offset, uint64_t len,
+  FDRef fd, const ghobject_t &hoid, uint64_t offset, uint64_t len,
   bool nocache)
 {
   Mutex::Locker l(lock);
-  map<hobject_t, pair<PendingWB, FDRef> >::iterator wbiter =
+  map<ghobject_t, pair<PendingWB, FDRef> >::iterator wbiter =
     pending_wbs.find(hoid);
   if (wbiter == pending_wbs.end()) {
     wbiter = pending_wbs.insert(
@@ -192,7 +192,7 @@ void WBThrottle::queue_wb(
 void WBThrottle::clear()
 {
   Mutex::Locker l(lock);
-  for (map<hobject_t, pair<PendingWB, FDRef> >::iterator i =
+  for (map<ghobject_t, pair<PendingWB, FDRef> >::iterator i =
 	 pending_wbs.begin();
        i != pending_wbs.end();
        ++i) {
@@ -208,12 +208,12 @@ void WBThrottle::clear()
   cond.Signal();
 }
 
-void WBThrottle::clear_object(const hobject_t &hoid)
+void WBThrottle::clear_object(const ghobject_t &hoid)
 {
   Mutex::Locker l(lock);
   while (clearing == hoid)
     cond.Wait(lock);
-  map<hobject_t, pair<PendingWB, FDRef> >::iterator i =
+  map<ghobject_t, pair<PendingWB, FDRef> >::iterator i =
     pending_wbs.find(hoid);
   if (i == pending_wbs.end())
     return;
diff --git a/src/os/WBThrottle.h b/src/os/WBThrottle.h
index d480a6b751c..e418cf98d2a 100644
--- a/src/os/WBThrottle.h
+++ b/src/os/WBThrottle.h
@@ -44,7 +44,7 @@ enum {
  * Tracks, throttles, and flushes outstanding IO
  */
 class WBThrottle : Thread, public md_config_obs_t {
-  hobject_t clearing;
+  ghobject_t clearing;
 
   /* *_limits.first is the start_flusher limit and
    * *_limits.second is the hard limit
@@ -89,36 +89,36 @@ class WBThrottle : Thread, public md_config_obs_t {
   /**
    * Flush objects in lru order
    */
-  list<hobject_t> lru;
-  map<hobject_t, list<hobject_t>::iterator> rev_lru;
-  void remove_object(const hobject_t &hoid) {
+  list<ghobject_t> lru;
+  map<ghobject_t, list<ghobject_t>::iterator> rev_lru;
+  void remove_object(const ghobject_t &oid) {
     assert(lock.is_locked());
-    map<hobject_t, list<hobject_t>::iterator>::iterator iter =
-      rev_lru.find(hoid);
+    map<ghobject_t, list<ghobject_t>::iterator>::iterator iter =
+      rev_lru.find(oid);
     if (iter == rev_lru.end())
       return;
 
     lru.erase(iter->second);
     rev_lru.erase(iter);
   }
-  hobject_t pop_object() {
+  ghobject_t pop_object() {
     assert(!lru.empty());
-    hobject_t hoid(lru.front());
+    ghobject_t oid(lru.front());
     lru.pop_front();
-    rev_lru.erase(hoid);
-    return hoid;
+    rev_lru.erase(oid);
+    return oid;
   }
-  void insert_object(const hobject_t &hoid) {
-    assert(rev_lru.find(hoid) == rev_lru.end());
-    lru.push_back(hoid);
-    rev_lru.insert(make_pair(hoid, --lru.end()));
+  void insert_object(const ghobject_t &oid) {
+    assert(rev_lru.find(oid) == rev_lru.end());
+    lru.push_back(oid);
+    rev_lru.insert(make_pair(oid, --lru.end()));
   }
 
-  map<hobject_t, pair<PendingWB, FDRef> > pending_wbs;
+  map<ghobject_t, pair<PendingWB, FDRef> > pending_wbs;
 
   /// get next flush to perform
   bool get_next_should_flush(
-    boost::tuple<hobject_t, FDRef, PendingWB> *next ///< [out] next to flush
+    boost::tuple<ghobject_t, FDRef, PendingWB> *next ///< [out] next to flush
     ); ///< @return false if we are shutting down
 public:
   enum FS {
@@ -141,10 +141,10 @@ public:
     set_from_conf();
   }
 
-  /// Queue wb on hoid, fd taking throttle (does not block)
+  /// Queue wb on oid, fd taking throttle (does not block)
   void queue_wb(
-    FDRef fd,              ///< [in] FDRef to hoid
-    const hobject_t &hoid, ///< [in] object
+    FDRef fd,              ///< [in] FDRef to oid
+    const ghobject_t &oid, ///< [in] object
     uint64_t offset,       ///< [in] offset written
     uint64_t len,          ///< [in] length written
     bool nocache           ///< [in] try to clear out of cache after write
@@ -154,7 +154,7 @@ public:
   void clear();
 
   /// Clear object
-  void clear_object(const hobject_t &hoid);
+  void clear_object(const ghobject_t &oid);
 
   /// Block until there is throttle available
   void throttle();
diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index df1b111a2a9..4013350f9d2 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -158,6 +158,7 @@ CompatSet OSD::get_osd_initial_compat_set() {
 CompatSet OSD::get_osd_compat_set() {
   CompatSet compat =  get_osd_initial_compat_set();
   //Any features here can be set in code, but not in initial superblock
+  compat.incompat.insert(CEPH_OSD_FEATURE_INCOMPAT_SHARDS);
   return compat;
 }
 
@@ -458,7 +459,7 @@ int OSD::convert_collection(ObjectStore *store, coll_t cid)
 {
   coll_t tmp0("convertfs_temp");
   coll_t tmp1("convertfs_temp1");
-  vector<hobject_t> objects;
+  vector<ghobject_t> objects;
 
   map<string, bufferptr> aset;
   int r = store->collection_getattrs(cid, aset);
@@ -478,10 +479,10 @@ int OSD::convert_collection(ObjectStore *store, coll_t cid)
     store->apply_transaction(t);
   }
 
-  hobject_t next;
+  ghobject_t next;
   while (!next.is_max()) {
     objects.clear();
-    hobject_t start = next;
+    ghobject_t start = next;
     r = store->collection_list_partial(cid, start,
 				       200, 300, 0,
 				       &objects, &next);
@@ -489,7 +490,7 @@ int OSD::convert_collection(ObjectStore *store, coll_t cid)
       return r;
 
     ObjectStore::Transaction t;
-    for (vector<hobject_t>::iterator i = objects.begin();
+    for (vector<ghobject_t>::iterator i = objects.begin();
 	 i != objects.end();
 	 ++i) {
       t.collection_add(tmp0, cid, *i);
@@ -1198,11 +1199,11 @@ int OSD::init()
   }
 
   CompatSet initial = get_osd_initial_compat_set();
-  if (initial.compare(superblock.compat_features) != 0) {
+  CompatSet diff = superblock.compat_features.unsupported(initial);
+  if (superblock.compat_features.merge(initial)) {
     // We need to persist the new compat_set before we
     // do anything else
-    dout(5) << "Upgrading superblock compat_set" << dendl;
-    superblock.compat_features = initial;
+    dout(5) << "Upgrading superblock adding: " << diff << dendl;
     ObjectStore::Transaction t;
     write_superblock(t);
     r = store->apply_transaction(t);
@@ -1761,17 +1762,17 @@ void OSD::recursive_remove_collection(ObjectStore *store, coll_t tmp)
     make_snapmapper_oid());
   SnapMapper mapper(&driver, 0, 0, 0);
 
-  vector<hobject_t> objects;
+  vector<ghobject_t> objects;
   store->collection_list(tmp, objects);
 
   // delete them.
   ObjectStore::Transaction t;
   unsigned removed = 0;
-  for (vector<hobject_t>::iterator p = objects.begin();
+  for (vector<ghobject_t>::iterator p = objects.begin();
        p != objects.end();
        ++p, removed++) {
     OSDriver::OSTransaction _t(driver.get_transaction(&t));
-    int r = mapper.remove_oid(*p, &_t);
+    int r = mapper.remove_oid(p->hobj, &_t);
     if (r != 0 && r != -ENOENT)
       assert(0);
     t.collection_remove(tmp, *p);
@@ -3352,10 +3353,10 @@ bool remove_dir(
   ObjectStore::Sequencer *osr,
   coll_t coll, DeletingStateRef dstate)
 {
-  vector<hobject_t> olist;
+  vector<ghobject_t> olist;
   int64_t num = 0;
   ObjectStore::Transaction *t = new ObjectStore::Transaction;
-  hobject_t next;
+  ghobject_t next;
   while (!next.is_max()) {
     store->collection_list_partial(
       coll,
@@ -3365,11 +3366,11 @@ bool remove_dir(
       0,
       &olist,
       &next);
-    for (vector<hobject_t>::iterator i = olist.begin();
+    for (vector<ghobject_t>::iterator i = olist.begin();
 	 i != olist.end();
 	 ++i, ++num) {
       OSDriver::OSTransaction _t(osdriver->get_transaction(t));
-      int r = mapper->remove_oid(*i, &_t);
+      int r = mapper->remove_oid(i->hobj, &_t);
       if (r != 0 && r != -ENOENT) {
 	assert(0);
       }
diff --git a/src/osd/PGLog.cc b/src/osd/PGLog.cc
index 486d64302b9..b95716f998e 100644
--- a/src/osd/PGLog.cc
+++ b/src/osd/PGLog.cc
@@ -784,7 +784,7 @@ void PGLog::read_log_old(ObjectStore *store, coll_t coll, hobject_t log_oid,
 
   // In case of sobject_t based encoding, may need to list objects in the store
   // to find hashes
-  vector<hobject_t> ls;
+  vector<ghobject_t> ls;
   
   if (ondisklog_head > 0) {
     // read
@@ -853,11 +853,13 @@ void PGLog::read_log_old(ObjectStore *store, coll_t coll, hobject_t log_oid,
 	  listed_collection = true;
 	}
 	bool found = false;
-	for (vector<hobject_t>::iterator i = ls.begin();
+	for (vector<ghobject_t>::iterator i = ls.begin();
 	     i != ls.end();
 	     ++i) {
-	  if (i->oid == e.soid.oid && i->snap == e.soid.snap) {
-	    e.soid = *i;
+          // Older OSD can't have new format objects
+          assert(i->generation == ghobject_t::NO_GEN);
+	  if (i->hobj.oid == e.soid.oid && i->hobj.snap == e.soid.snap) {
+	    e.soid = i->hobj;
 	    found = true;
 	    break;
 	  }
diff --git a/src/test/ObjectMap/test_object_map.cc b/src/test/ObjectMap/test_object_map.cc
index 1b39c8068fb..23f220daf45 100644
--- a/src/test/ObjectMap/test_object_map.cc
+++ b/src/test/ObjectMap/test_object_map.cc
@@ -55,16 +55,16 @@ public:
   }
 
   void set_key(const string &objname, const string &key, const string &value) {
-    set_key(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
+    set_key(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
 	    key, value);
   }
 
   void set_xattr(const string &objname, const string &key, const string &value) {
-    set_xattr(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
+    set_xattr(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
 	      key, value);
   }
 
-  void set_key(hobject_t hoid,
+  void set_key(ghobject_t hoid,
 	       string key, string value) {
     map<string, bufferlist> to_write;
     bufferptr bp(value.c_str(), value.size());
@@ -74,7 +74,7 @@ public:
     db->set_keys(hoid, to_write);
   }
 
-  void set_xattr(hobject_t hoid,
+  void set_xattr(ghobject_t hoid,
 		 string key, string value) {
     map<string, bufferlist> to_write;
     bufferptr bp(value.c_str(), value.size());
@@ -85,11 +85,11 @@ public:
   }
 
   void set_header(const string &objname, const string &value) {
-    set_header(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
+    set_header(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
 	       value);
   }
 
-  void set_header(hobject_t hoid,
+  void set_header(ghobject_t hoid,
 		  const string &value) {
     bufferlist header;
     header.append(bufferptr(value.c_str(), value.size() + 1));
@@ -97,11 +97,11 @@ public:
   }
 
   int get_header(const string &objname, string *value) {
-    return get_header(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
+    return get_header(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
 		      value);
   }
 
-  int get_header(hobject_t hoid,
+  int get_header(ghobject_t hoid,
 		 string *value) {
     bufferlist header;
     int r = db->get_header(hoid, &header);
@@ -115,11 +115,11 @@ public:
   }
 
   int get_xattr(const string &objname, const string &key, string *value) {
-    return get_xattr(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
+    return get_xattr(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
 		     key, value);
   }
 
-  int get_xattr(hobject_t hoid,
+  int get_xattr(ghobject_t hoid,
 		string key, string *value) {
     set<string> to_get;
     to_get.insert(key);
@@ -135,11 +135,11 @@ public:
   }
 
   int get_key(const string &objname, const string &key, string *value) {
-    return get_key(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
+    return get_key(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
 		   key, value);
   }
 
-  int get_key(hobject_t hoid,
+  int get_key(ghobject_t hoid,
 	      string key, string *value) {
     set<string> to_get;
     to_get.insert(key);
@@ -155,11 +155,11 @@ public:
   }
 
   void remove_key(const string &objname, const string &key) {
-    remove_key(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
+    remove_key(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
 	       key);
   }
 
-  void remove_key(hobject_t hoid,
+  void remove_key(ghobject_t hoid,
 		  string key) {
     set<string> to_remove;
     to_remove.insert(key);
@@ -167,11 +167,11 @@ public:
   }
 
   void remove_xattr(const string &objname, const string &key) {
-    remove_xattr(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
+    remove_xattr(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
 		 key);
   }
 
-  void remove_xattr(hobject_t hoid,
+  void remove_xattr(ghobject_t hoid,
 		    string key) {
     set<string> to_remove;
     to_remove.insert(key);
@@ -179,20 +179,20 @@ public:
   }
 
   void clone(const string &objname, const string &target) {
-    clone(hobject_t(sobject_t(objname, CEPH_NOSNAP)),
-	  hobject_t(sobject_t(target, CEPH_NOSNAP)));
+    clone(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))),
+	  ghobject_t(hobject_t(sobject_t(target, CEPH_NOSNAP))));
   }
 
-  void clone(hobject_t hoid,
-	     hobject_t hoid2) {
+  void clone(ghobject_t hoid,
+	     ghobject_t hoid2) {
     db->clone(hoid, hoid2);
   }
 
   void clear(const string &objname) {
-    clear(hobject_t(sobject_t(objname, CEPH_NOSNAP)));
+    clear(ghobject_t(hobject_t(sobject_t(objname, CEPH_NOSNAP))));
   }
 
-  void clear(hobject_t hoid) {
+  void clear(ghobject_t hoid) {
     db->clear(hoid);
   }
 
@@ -543,7 +543,7 @@ int main(int argc, char **argv) {
 }
 
 TEST_F(ObjectMapTest, CreateOneObject) {
-  hobject_t hoid(sobject_t("foo", CEPH_NOSNAP));
+  ghobject_t hoid(hobject_t(sobject_t("foo", CEPH_NOSNAP)), 100, 0);
   map<string, bufferlist> to_set;
   string key("test");
   string val("test_val");
@@ -579,8 +579,8 @@ TEST_F(ObjectMapTest, CreateOneObject) {
 }
 
 TEST_F(ObjectMapTest, CloneOneObject) {
-  hobject_t hoid(sobject_t("foo", CEPH_NOSNAP));
-  hobject_t hoid2(sobject_t("foo2", CEPH_NOSNAP));
+  ghobject_t hoid(hobject_t(sobject_t("foo", CEPH_NOSNAP)), 200, 0);
+  ghobject_t hoid2(hobject_t(sobject_t("foo2", CEPH_NOSNAP)), 201, 1);
 
   tester.set_key(hoid, "foo", "bar");
   tester.set_key(hoid, "foo2", "bar2");
@@ -640,8 +640,8 @@ TEST_F(ObjectMapTest, CloneOneObject) {
 }
 
 TEST_F(ObjectMapTest, OddEvenClone) {
-  hobject_t hoid(sobject_t("foo", CEPH_NOSNAP));
-  hobject_t hoid2(sobject_t("foo2", CEPH_NOSNAP));
+  ghobject_t hoid(hobject_t(sobject_t("foo", CEPH_NOSNAP)));
+  ghobject_t hoid2(hobject_t(sobject_t("foo2", CEPH_NOSNAP)));
 
   for (unsigned i = 0; i < 1000; ++i) {
     tester.set_key(hoid, "foo" + num_str(i), "bar" + num_str(i));
diff --git a/src/test/encoding/types.h b/src/test/encoding/types.h
index fe17f077d8e..7f2b4d9db5d 100644
--- a/src/test/encoding/types.h
+++ b/src/test/encoding/types.h
@@ -78,6 +78,7 @@ TYPE(SequencerPosition)
 
 #include "common/hobject.h"
 TYPE(hobject_t)
+TYPE(ghobject_t)
 
 #include "mon/AuthMonitor.h"
 TYPE(AuthMonitor::Incremental)
diff --git a/src/test/filestore/FileStoreDiff.cc b/src/test/filestore/FileStoreDiff.cc
index b2419f5e298..40c0b32d30c 100644
--- a/src/test/filestore/FileStoreDiff.cc
+++ b/src/test/filestore/FileStoreDiff.cc
@@ -131,7 +131,7 @@ bool FileStoreDiff::diff_objects(FileStore *a_store, FileStore *b_store, coll_t
   bool ret = false;
 
   int err;
-  std::vector<hobject_t> b_objects, a_objects;
+  std::vector<ghobject_t> b_objects, a_objects;
   err = b_store->collection_list(coll, b_objects);
   if (err < 0) {
     dout(0) << "diff_objects list on verify coll " << coll.to_str()
@@ -151,11 +151,11 @@ bool FileStoreDiff::diff_objects(FileStore *a_store, FileStore *b_store, coll_t
     ret = true;
   }
 
-  std::vector<hobject_t>::iterator b_it = b_objects.begin();
-  std::vector<hobject_t>::iterator a_it = b_objects.begin();
+  std::vector<ghobject_t>::iterator b_it = b_objects.begin();
+  std::vector<ghobject_t>::iterator a_it = b_objects.begin();
   for (; b_it != b_objects.end(); ++b_it, ++a_it) {
-    hobject_t b_obj = *b_it, a_obj = *a_it;
-    if (b_obj.oid.name != a_obj.oid.name) {
+    ghobject_t b_obj = *b_it, a_obj = *a_it;
+    if (b_obj.hobj.oid.name != a_obj.hobj.oid.name) {
       dout(0) << "diff_objects name mismatch on A object "
           << coll << "/" << a_obj << " and B object "
           << coll << "/" << b_obj << dendl;
@@ -167,7 +167,7 @@ bool FileStoreDiff::diff_objects(FileStore *a_store, FileStore *b_store, coll_t
     err = b_store->stat(coll, b_obj, &b_stat);
     if (err < 0) {
       dout(0) << "diff_objects error stating B object "
-	      << coll.to_str() << "/" << b_obj.oid.name << dendl;
+	      << coll.to_str() << "/" << b_obj.hobj.oid.name << dendl;
       ret = true;
     }
     err = a_store->stat(coll, a_obj, &a_stat);
diff --git a/src/test/filestore/store_test.cc b/src/test/filestore/store_test.cc
index 92104960127..50450f467ff 100644
--- a/src/test/filestore/store_test.cc
+++ b/src/test/filestore/store_test.cc
@@ -51,9 +51,9 @@ public:
   }
 };
 
-bool sorted(const vector<hobject_t> &in) {
-  hobject_t start;
-  for (vector<hobject_t>::const_iterator i = in.begin();
+bool sorted(const vector<ghobject_t> &in) {
+  ghobject_t start;
+  for (vector<ghobject_t>::const_iterator i = in.begin();
        i != in.end();
        ++i) {
     if (start > *i) return false;
@@ -105,7 +105,7 @@ TEST_F(StoreTest, SimpleObjectTest) {
     r = store->apply_transaction(t);
     ASSERT_EQ(r, 0);
   }
-  hobject_t hoid(sobject_t("Object 1", CEPH_NOSNAP));
+  ghobject_t hoid(hobject_t(sobject_t("Object 1", CEPH_NOSNAP)));
   {
     ObjectStore::Transaction t;
     t.touch(cid, hoid);
@@ -133,7 +133,7 @@ TEST_F(StoreTest, SimpleObjectLongnameTest) {
     r = store->apply_transaction(t);
     ASSERT_EQ(r, 0);
   }
-  hobject_t hoid(sobject_t("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaObjectaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 1", CEPH_NOSNAP));
+  ghobject_t hoid(hobject_t(sobject_t("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaObjectaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa 1", CEPH_NOSNAP)));
   {
     ObjectStore::Transaction t;
     t.touch(cid, hoid);
@@ -157,7 +157,7 @@ TEST_F(StoreTest, ManyObjectTest) {
   coll_t cid("blah");
   string base = "";
   for (int i = 0; i < 100; ++i) base.append("aaaaa");
-  set<hobject_t> created;
+  set<ghobject_t> created;
   {
     ObjectStore::Transaction t;
     t.create_collection(cid);
@@ -171,27 +171,27 @@ TEST_F(StoreTest, ManyObjectTest) {
     ObjectStore::Transaction t;
     char buf[100];
     snprintf(buf, sizeof(buf), "%d", i);
-    hobject_t hoid(sobject_t(string(buf) + base, CEPH_NOSNAP));
+    ghobject_t hoid(hobject_t(sobject_t(string(buf) + base, CEPH_NOSNAP)));
     t.touch(cid, hoid);
     created.insert(hoid);
     r = store->apply_transaction(t);
     ASSERT_EQ(r, 0);
   }
 
-  for (set<hobject_t>::iterator i = created.begin();
+  for (set<ghobject_t>::iterator i = created.begin();
        i != created.end();
        ++i) {
     struct stat buf;
     ASSERT_TRUE(!store->stat(cid, *i, &buf));
   }
 
-  set<hobject_t> listed;
-  vector<hobject_t> objects;
+  set<ghobject_t> listed;
+  vector<ghobject_t> objects;
   r = store->collection_list(cid, objects);
   ASSERT_EQ(r, 0);
 
   cerr << "objects.size() is " << objects.size() << std::endl;
-  for (vector<hobject_t> ::iterator i = objects.begin();
+  for (vector<ghobject_t> ::iterator i = objects.begin();
        i != objects.end();
        ++i) {
     listed.insert(*i);
@@ -199,11 +199,11 @@ TEST_F(StoreTest, ManyObjectTest) {
   }
   ASSERT_TRUE(listed.size() == created.size());
 
-  hobject_t start, next;
+  ghobject_t start, next;
   objects.clear();
   r = store->collection_list_partial(
     cid,
-    hobject_t::get_max(),
+    ghobject_t::get_max(),
     50,
     60,
     0,
@@ -234,13 +234,13 @@ TEST_F(StoreTest, ManyObjectTest) {
   }
   cerr << "listed.size() is " << listed.size() << std::endl;
   ASSERT_TRUE(listed.size() == created.size());
-  for (set<hobject_t>::iterator i = listed.begin();
+  for (set<ghobject_t>::iterator i = listed.begin();
        i != listed.end();
        ++i) {
     ASSERT_TRUE(created.count(*i));
   }
 
-  for (set<hobject_t>::iterator i = created.begin();
+  for (set<ghobject_t>::iterator i = created.begin();
        i != created.end();
        ++i) {
     ObjectStore::Transaction t;
@@ -259,7 +259,7 @@ TEST_F(StoreTest, ManyObjectTest) {
 
 class ObjectGenerator {
 public:
-  virtual hobject_t create_object(gen_type *gen) = 0;
+  virtual ghobject_t create_object(gen_type *gen) = 0;
   virtual ~ObjectGenerator() {}
 };
 
@@ -267,7 +267,7 @@ class MixedGenerator : public ObjectGenerator {
 public:
   unsigned seq;
   MixedGenerator() : seq(0) {}
-  hobject_t create_object(gen_type *gen) {
+  ghobject_t create_object(gen_type *gen) {
     char buf[100];
     snprintf(buf, sizeof(buf), "%u", seq);
 
@@ -283,7 +283,7 @@ public:
     // hash
     //boost::binomial_distribution<uint32_t> bin(0xFFFFFF, 0.5);
     ++seq;
-    return hobject_t(name, string(), rand() & 2 ? CEPH_NOSNAP : rand(), rand() & 0xFF, 0, "");
+    return ghobject_t(hobject_t(name, string(), rand() & 2 ? CEPH_NOSNAP : rand(), rand() & 0xFF, 0, ""));
   }
 };
 
@@ -293,8 +293,8 @@ public:
   static const unsigned max_objects = 3000;
   coll_t cid;
   unsigned in_flight;
-  set<hobject_t> available_objects;
-  set<hobject_t> in_use_objects;
+  set<ghobject_t> available_objects;
+  set<ghobject_t> in_use_objects;
   ObjectGenerator *object_gen;
   gen_type *rng;
   ObjectStore *store;
@@ -307,9 +307,9 @@ public:
   public:
     SyntheticWorkloadState *state;
     ObjectStore::Transaction *t;
-    hobject_t hoid;
+    ghobject_t hoid;
     C_SyntheticOnReadable(SyntheticWorkloadState *state,
-			  ObjectStore::Transaction *t, hobject_t hoid)
+			  ObjectStore::Transaction *t, ghobject_t hoid)
       : state(state), t(t), hoid(hoid) {}
 
     void finish(int r) {
@@ -339,14 +339,14 @@ public:
     return store->apply_transaction(t);
   }
 
-  hobject_t get_uniform_random_object() {
+  ghobject_t get_uniform_random_object() {
     while (in_flight >= max_in_flight || available_objects.empty())
       cond.Wait(lock);
     boost::uniform_int<> choose(0, available_objects.size() - 1);
     int index = choose(*rng);
-    set<hobject_t>::iterator i = available_objects.begin();
+    set<ghobject_t>::iterator i = available_objects.begin();
     for ( ; index > 0; --index, ++i) ;
-    hobject_t ret = *i;
+    ghobject_t ret = *i;
     available_objects.erase(i);
     return ret;
   }
@@ -375,7 +375,7 @@ public:
     if (!can_create())
       return -ENOSPC;
     wait_for_ready();
-    hobject_t new_obj = object_gen->create_object(rng);
+    ghobject_t new_obj = object_gen->create_object(rng);
     in_use_objects.insert(new_obj);
     available_objects.erase(new_obj);
     ObjectStore::Transaction *t = new ObjectStore::Transaction;
@@ -388,9 +388,9 @@ public:
     Mutex::Locker locker(lock);
     while (in_flight)
       cond.Wait(lock);
-    vector<hobject_t> objects;
-    set<hobject_t> objects_set, objects_set2;
-    hobject_t next, current;
+    vector<ghobject_t> objects;
+    set<ghobject_t> objects_set, objects_set2;
+    ghobject_t next, current;
     while (1) {
       cerr << "scanning..." << std::endl;
       int r = store->collection_list_partial(cid, current, 50, 100, 
@@ -403,7 +403,7 @@ public:
       current = next;
     }
     ASSERT_EQ(objects_set.size(), available_objects.size());
-    for (set<hobject_t>::iterator i = objects_set.begin();
+    for (set<ghobject_t>::iterator i = objects_set.begin();
 	 i != objects_set.end();
 	 ++i) {
       ASSERT_GT(available_objects.count(*i), (unsigned)0);
@@ -413,7 +413,7 @@ public:
     ASSERT_EQ(r, 0);
     objects_set2.insert(objects.begin(), objects.end());
     ASSERT_EQ(objects_set2.size(), available_objects.size());
-    for (set<hobject_t>::iterator i = objects_set2.begin();
+    for (set<ghobject_t>::iterator i = objects_set2.begin();
 	 i != objects_set2.end();
 	 ++i) {
       ASSERT_GT(available_objects.count(*i), (unsigned)0);
@@ -421,7 +421,7 @@ public:
   }
 
   int stat() {
-    hobject_t hoid;
+    ghobject_t hoid;
     {
       Mutex::Locker locker(lock);
       if (!can_unlink())
@@ -446,7 +446,7 @@ public:
     Mutex::Locker locker(lock);
     if (!can_unlink())
       return -ENOENT;
-    hobject_t to_remove = get_uniform_random_object();
+    ghobject_t to_remove = get_uniform_random_object();
     ObjectStore::Transaction *t = new ObjectStore::Transaction;
     t->remove(cid, to_remove);
     ++in_flight;
@@ -505,7 +505,7 @@ TEST_F(StoreTest, HashCollisionTest) {
   }
   string base = "";
   for (int i = 0; i < 100; ++i) base.append("aaaaa");
-  set<hobject_t> created;
+  set<ghobject_t> created;
   for (int n = 0; n < 10; ++n) {
     char nbuf[100];
     sprintf(nbuf, "n%d", n);
@@ -515,7 +515,7 @@ TEST_F(StoreTest, HashCollisionTest) {
     if (!(i % 5)) {
       cerr << "Object n" << n << " "<< i << std::endl;
     }
-    hobject_t hoid(string(buf) + base, string(), CEPH_NOSNAP, 0, 0, string(nbuf));
+    ghobject_t hoid(hobject_t(string(buf) + base, string(), CEPH_NOSNAP, 0, 0, string(nbuf)));
     {
       ObjectStore::Transaction t;
       t.touch(cid, hoid);
@@ -525,21 +525,21 @@ TEST_F(StoreTest, HashCollisionTest) {
     created.insert(hoid);
   }
   }
-  vector<hobject_t> objects;
+  vector<ghobject_t> objects;
   r = store->collection_list(cid, objects);
   ASSERT_EQ(r, 0);
-  set<hobject_t> listed(objects.begin(), objects.end());
+  set<ghobject_t> listed(objects.begin(), objects.end());
   cerr << "listed.size() is " << listed.size() << " and created.size() is " << created.size() << std::endl;
   ASSERT_TRUE(listed.size() == created.size());
   objects.clear();
   listed.clear();
-  hobject_t current, next;
+  ghobject_t current, next;
   while (1) {
     r = store->collection_list_partial(cid, current, 50, 60,
 				       0, &objects, &next);
     ASSERT_EQ(r, 0);
     ASSERT_TRUE(sorted(objects));
-    for (vector<hobject_t>::iterator i = objects.begin();
+    for (vector<ghobject_t>::iterator i = objects.begin();
 	 i != objects.end();
 	 ++i) {
       if (listed.count(*i))
@@ -555,13 +555,13 @@ TEST_F(StoreTest, HashCollisionTest) {
   }
   cerr << "listed.size() is " << listed.size() << std::endl;
   ASSERT_TRUE(listed.size() == created.size());
-  for (set<hobject_t>::iterator i = listed.begin();
+  for (set<ghobject_t>::iterator i = listed.begin();
        i != listed.end();
        ++i) {
     ASSERT_TRUE(created.count(*i));
   }
 
-  for (set<hobject_t>::iterator i = created.begin();
+  for (set<ghobject_t>::iterator i = created.begin();
        i != created.end();
        ++i) {
     ObjectStore::Transaction t;
@@ -576,7 +576,7 @@ TEST_F(StoreTest, HashCollisionTest) {
 
 TEST_F(StoreTest, OMapTest) {
   coll_t cid("blah");
-  hobject_t hoid("tesomap", "", CEPH_NOSNAP, 0, 0, "");
+  ghobject_t hoid(hobject_t("tesomap", "", CEPH_NOSNAP, 0, 0, ""));
   int r;
   {
     ObjectStore::Transaction t;
@@ -672,7 +672,7 @@ TEST_F(StoreTest, OMapTest) {
 
 TEST_F(StoreTest, XattrTest) {
   coll_t cid("blah");
-  hobject_t hoid("tesomap", "", CEPH_NOSNAP, 0, 0, "");
+  ghobject_t hoid(hobject_t("tesomap", "", CEPH_NOSNAP, 0, 0, ""));
   bufferlist big;
   for (unsigned i = 0; i < 10000; ++i) {
     big.append('\0');
@@ -769,12 +769,12 @@ void colsplittest(
     for (uint32_t i = 0; i < 2*num_objects; ++i) {
       stringstream objname;
       objname << "obj" << i;
-      t.touch(cid, hobject_t(
+      t.touch(cid, ghobject_t(hobject_t(
 	  objname.str(),
 	  "",
 	  CEPH_NOSNAP,
 	  i<<common_suffix_size,
-	  0, ""));
+	  0, "")));
     }
     r = store->apply_transaction(t);
     ASSERT_EQ(r, 0);
@@ -788,14 +788,14 @@ void colsplittest(
   }
 
   ObjectStore::Transaction t;
-  vector<hobject_t> objects;
+  vector<ghobject_t> objects;
   r = store->collection_list(cid, objects);
   ASSERT_EQ(r, 0);
   ASSERT_EQ(objects.size(), num_objects);
-  for (vector<hobject_t>::iterator i = objects.begin();
+  for (vector<ghobject_t>::iterator i = objects.begin();
        i != objects.end();
        ++i) {
-    ASSERT_EQ(!(i->hash & (1<<common_suffix_size)), 0u);
+    ASSERT_EQ(!(i->hobj.hash & (1<<common_suffix_size)), 0u);
     t.remove(cid, *i);
   }
 
@@ -803,10 +803,10 @@ void colsplittest(
   r = store->collection_list(tid, objects);
   ASSERT_EQ(r, 0);
   ASSERT_EQ(objects.size(), num_objects);
-  for (vector<hobject_t>::iterator i = objects.begin();
+  for (vector<ghobject_t>::iterator i = objects.begin();
        i != objects.end();
        ++i) {
-    ASSERT_EQ(i->hash & (1<<common_suffix_size), 0u);
+    ASSERT_EQ(i->hobj.hash & (1<<common_suffix_size), 0u);
     t.remove(tid, *i);
   }
 
@@ -848,12 +848,12 @@ TEST_F(StoreTest, TwoHash) {
   std::cout << "Making objects" << std::endl;
   for (int i = 0; i < 360; ++i) {
     ObjectStore::Transaction t;
-    hobject_t o;
+    ghobject_t o;
     if (i < 8) {
-      o.hash = (i << 16) | 0xA1;
+      o.hobj.hash = (i << 16) | 0xA1;
       t.touch(cid, o);
     }
-    o.hash = (i << 16) | 0xB1;
+    o.hobj.hash = (i << 16) | 0xB1;
     t.touch(cid, o);
     r = store->apply_transaction(t);
     ASSERT_EQ(r, 0);
@@ -861,8 +861,8 @@ TEST_F(StoreTest, TwoHash) {
   std::cout << "Removing half" << std::endl;
   for (int i = 1; i < 8; ++i) {
     ObjectStore::Transaction t;
-    hobject_t o;
-    o.hash = (i << 16) | 0xA1;
+    ghobject_t o;
+    o.hobj.hash = (i << 16) | 0xA1;
     t.remove(cid, o);
     r = store->apply_transaction(t);
     ASSERT_EQ(r, 0);
@@ -870,24 +870,24 @@ TEST_F(StoreTest, TwoHash) {
   std::cout << "Checking" << std::endl;
   for (int i = 1; i < 8; ++i) {
     ObjectStore::Transaction t;
-    hobject_t o;
-    o.hash = (i << 16) | 0xA1;
+    ghobject_t o;
+    o.hobj.hash = (i << 16) | 0xA1;
     bool exists = store->exists(cid, o);
     ASSERT_EQ(exists, false);
   }
   {
-    hobject_t o;
-    o.hash = 0xA1;
+    ghobject_t o;
+    o.hobj.hash = 0xA1;
     bool exists = store->exists(cid, o);
     ASSERT_EQ(exists, true);
   }
   std::cout << "Cleanup" << std::endl;
   for (int i = 0; i < 360; ++i) {
     ObjectStore::Transaction t;
-    hobject_t o;
-    o.hash = (i << 16) | 0xA1;
+    ghobject_t o;
+    o.hobj.hash = (i << 16) | 0xA1;
     t.remove(cid, o);
-    o.hash = (i << 16) | 0xB1;
+    o.hobj.hash = (i << 16) | 0xB1;
     t.remove(cid, o);
     r = store->apply_transaction(t);
     ASSERT_EQ(r, 0);
diff --git a/src/test/filestore/workload_generator.cc b/src/test/filestore/workload_generator.cc
index 496379d7ad1..704d93021e2 100644
--- a/src/test/filestore/workload_generator.cc
+++ b/src/test/filestore/workload_generator.cc
@@ -344,12 +344,12 @@ void WorkloadGenerator::do_destroy_collection(ObjectStore::Transaction *t,
 {  
   m_nr_runs.set(0);
   entry->m_osr.flush();
-  vector<hobject_t> ls;
+  vector<ghobject_t> ls;
   m_store->collection_list(entry->m_coll, ls);
   dout(2) << __func__ << " coll " << entry->m_coll
       << " (" << ls.size() << " objects)" << dendl;
 
-  for (vector<hobject_t>::iterator it = ls.begin(); it < ls.end(); ++it) {
+  for (vector<ghobject_t>::iterator it = ls.begin(); it < ls.end(); ++it) {
     t->remove(entry->m_coll, *it);
   }
 
diff --git a/src/test/os/TestFlatIndex.cc b/src/test/os/TestFlatIndex.cc
index 6db4f6c4aa5..53d2bbe6376 100644
--- a/src/test/os/TestFlatIndex.cc
+++ b/src/test/os/TestFlatIndex.cc
@@ -49,8 +49,8 @@ TEST(FlatIndex, collection) {
   uint64_t hash = 111;
   uint64_t pool = 222;
   const std::string object_name(10, 'A');
-  hobject_t hoid(object_t(object_name), key, CEPH_NOSNAP, hash, pool, "");
-  vector<hobject_t> ls;
+  ghobject_t hoid(hobject_t(object_t(object_name), key, CEPH_NOSNAP, hash, pool, ""));
+  vector<ghobject_t> ls;
   ASSERT_DEATH(index.collection_list_partial(hoid, 0, 0, 0, &ls, &hoid), "0");
 }
 
@@ -70,7 +70,7 @@ TEST(FlatIndex, created_unlink) {
     CollectionIndex::IndexedPath indexed_path;
     index->set_ref(index);
     const std::string object_name(10, 'A');
-    hobject_t hoid(object_t(object_name), key, CEPH_NOSNAP, hash, pool, "");
+    ghobject_t hoid(hobject_t(object_t(object_name), key, CEPH_NOSNAP, hash, pool, ""));
     int exists;
     EXPECT_EQ(0, index->lookup(hoid, &indexed_path, &exists));
     EXPECT_EQ(0, exists);
@@ -88,7 +88,7 @@ TEST(FlatIndex, created_unlink) {
     CollectionIndex::IndexedPath indexed_path;
     index->set_ref(index);
     const std::string object_name(1024, 'A');
-    hobject_t hoid(object_t(object_name), key, CEPH_NOSNAP, hash, pool, "");
+    ghobject_t hoid(hobject_t(object_t(object_name), key, CEPH_NOSNAP, hash, pool, ""));
     int exists;
     EXPECT_EQ(0, index->lookup(hoid, &indexed_path, &exists));
     EXPECT_EQ(0, exists);
@@ -110,10 +110,10 @@ TEST(FlatIndex, collection_list) {
   const std::string filename("PATH/" + object_name + "_head");
   EXPECT_EQ(0, ::close(::creat(filename.c_str(), 0600)));
   std::tr1::shared_ptr<CollectionIndex> index(new FlatIndex(collection, base_path));
-  vector<hobject_t> ls;
+  vector<ghobject_t> ls;
   index->collection_list(&ls);
   EXPECT_EQ((unsigned)1, ls.size());
-  EXPECT_EQ(object_name, ls[0].oid.name);
+  EXPECT_EQ(object_name, ls[0].hobj.oid.name);
   EXPECT_EQ(0, ::system("rm -fr PATH"));
 }
 
diff --git a/src/test/os/TestLFNIndex.cc b/src/test/os/TestLFNIndex.cc
index 3947329d995..58e412a454a 100644
--- a/src/test/os/TestLFNIndex.cc
+++ b/src/test/os/TestLFNIndex.cc
@@ -45,10 +45,10 @@ public:
 		     std::tr1::shared_ptr<CollectionIndex> dest
 		     ) { return 0; }
 
-  void test_generate_and_parse(const hobject_t &hoid, const std::string &mangled_expected) {
+  void test_generate_and_parse(const ghobject_t &hoid, const std::string &mangled_expected) {
     const std::string mangled_name = lfn_generate_object_name(hoid);
     EXPECT_EQ(mangled_expected, mangled_name);
-    hobject_t hoid_parsed;
+    ghobject_t hoid_parsed;
     EXPECT_TRUE(lfn_parse_object_name(mangled_name, &hoid_parsed));
     EXPECT_EQ(hoid, hoid_parsed);
   }
@@ -58,34 +58,34 @@ protected:
 
   virtual int _created(
 		       const vector<string> &path,
-		       const hobject_t &hoid,     
+		       const ghobject_t &hoid,
 		       const string &mangled_name 
 		       ) { return 0; }
 
   virtual int _remove(
 		      const vector<string> &path,
-		      const hobject_t &hoid,    
+		      const ghobject_t &hoid,
 		      const string &mangled_name
 		      ) { return 0; }
 
   virtual int _lookup(
-		      const hobject_t &hoid,
+		      const ghobject_t &hoid,
 		      vector<string> *path,
 		      string *mangled_name,
 		      int *exists		 
 		      ) { return 0; }
 
   virtual int _collection_list(
-			       vector<hobject_t> *ls
+			       vector<ghobject_t> *ls
 			       ) { return 0; }
 
   virtual int _collection_list_partial(
-				       const hobject_t &start,
+				       const ghobject_t &start,
 				       int min_count,
 				       int max_count,
 				       snapid_t seq,
-				       vector<hobject_t> *ls,
-				       hobject_t *next
+				       vector<ghobject_t> *ls,
+				       ghobject_t *next
 				       ) { return 0; }
 };
 
@@ -101,9 +101,9 @@ TEST_F(TestHASH_INDEX_TAG, generate_and_parse_name) {
   uint64_t hash = 0xABABABAB;
   uint64_t pool = -1;
 
-  test_generate_and_parse(hobject_t(object_t(".A/B_\\C.D"), key, CEPH_NOSNAP, hash, pool, ""),
+  test_generate_and_parse(ghobject_t(hobject_t(object_t(".A/B_\\C.D"), key, CEPH_NOSNAP, hash, pool, "")),
 			  "\\.A\\sB_\\\\C.D_head_ABABABAB");
-  test_generate_and_parse(hobject_t(object_t("DIR_A"), key, CEPH_NOSNAP, hash, pool, ""),
+  test_generate_and_parse(ghobject_t(hobject_t(object_t("DIR_A"), key, CEPH_NOSNAP, hash, pool, "")),
 			  "\\dA_head_ABABABAB");
 }
 
@@ -123,11 +123,11 @@ TEST_F(TestHASH_INDEX_TAG_2, generate_and_parse_name) {
   {
     std::string name(".XA/B_\\C.D");
     name[1] = '\0';
-    hobject_t hoid(object_t(name), key, CEPH_NOSNAP, hash, pool, "");
+    ghobject_t hoid(hobject_t(object_t(name), key, CEPH_NOSNAP, hash, pool, ""));
 
     test_generate_and_parse(hoid, "\\.\\nA\\sB\\u\\\\C.D_KEY_head_ABABABAB");
   }
-  test_generate_and_parse(hobject_t(object_t("DIR_A"), key, CEPH_NOSNAP, hash, pool, ""),
+  test_generate_and_parse(ghobject_t(hobject_t(object_t("DIR_A"), key, CEPH_NOSNAP, hash, pool, "")),
 			  "\\dA_KEY_head_ABABABAB");
 }
 
@@ -143,21 +143,37 @@ TEST_F(TestHOBJECT_WITH_POOL, generate_and_parse_name) {
   const std::string key("KEY");
   uint64_t hash = 0xABABABAB;
   uint64_t pool = 0xCDCDCDCD;
+  int64_t gen = 0xefefefefef;
+  int8_t shard_id = 0xb;
 
   {
     std::string name(".XA/B_\\C.D");
     name[1] = '\0';
-    hobject_t hoid(object_t(name), key, CEPH_NOSNAP, hash, pool, "");
-    hoid.nspace = "NSPACE";
+    ghobject_t hoid(hobject_t(object_t(name), key, CEPH_NOSNAP, hash, pool, ""));
+    hoid.hobj.nspace = "NSPACE";
 
     test_generate_and_parse(hoid, "\\.\\nA\\sB\\u\\\\C.D_KEY_head_ABABABAB_NSPACE_cdcdcdcd");
   }
   {
-    hobject_t hoid(object_t("DIR_A"), key, CEPH_NOSNAP, hash, pool, "");
-    hoid.nspace = "NSPACE";
+    ghobject_t hoid(hobject_t(object_t("DIR_A"), key, CEPH_NOSNAP, hash, pool, ""));
+    hoid.hobj.nspace = "NSPACE";
 
     test_generate_and_parse(hoid, "\\dA_KEY_head_ABABABAB_NSPACE_cdcdcdcd");
   }
+  {
+    std::string name(".XA/B_\\C.D");
+    name[1] = '\0';
+    ghobject_t hoid(hobject_t(object_t(name), key, CEPH_NOSNAP, hash, pool, ""), gen, shard_id);
+    hoid.hobj.nspace = "NSPACE";
+
+    test_generate_and_parse(hoid, "\\.\\nA\\sB\\u\\\\C.D_KEY_head_ABABABAB_NSPACE_cdcdcdcd_efefefefef_b");
+  }
+  {
+    ghobject_t hoid(hobject_t(object_t("DIR_A"), key, CEPH_NOSNAP, hash, pool, ""), gen, shard_id);
+    hoid.hobj.nspace = "NSPACE";
+
+    test_generate_and_parse(hoid, "\\dA_KEY_head_ABABABAB_NSPACE_cdcdcdcd_efefefefef_b");
+  }
 }
 
 class TestLFNIndex : public TestWrapLFNIndex, public ::testing::Test {
@@ -185,7 +201,7 @@ TEST_F(TestLFNIndex, remove_object) {
   {
     std::string mangled_name;
     int exists = 666;
-    hobject_t hoid(sobject_t("ABC", CEPH_NOSNAP));
+    ghobject_t hoid(hobject_t(sobject_t("ABC", CEPH_NOSNAP)));
 
     EXPECT_EQ(0, ::chmod("PATH", 0000));
     EXPECT_EQ(-EACCES, remove_object(path, hoid));
@@ -205,7 +221,7 @@ TEST_F(TestLFNIndex, remove_object) {
     std::string mangled_name;
     int exists;
     const std::string object_name(1024, 'A');
-    hobject_t hoid(sobject_t(object_name, CEPH_NOSNAP));
+    ghobject_t hoid(hobject_t(sobject_t(object_name, CEPH_NOSNAP)));
 
     EXPECT_EQ(0, get_mangled_name(path, hoid, &mangled_name, &exists));
     EXPECT_EQ(0, exists);
@@ -226,7 +242,7 @@ TEST_F(TestLFNIndex, remove_object) {
     std::string mangled_name;
     int exists;
     const std::string object_name(1024, 'A');
-    hobject_t hoid(sobject_t(object_name, CEPH_NOSNAP));
+    ghobject_t hoid(hobject_t(sobject_t(object_name, CEPH_NOSNAP)));
 
     //
     //   PATH/AAA..._0_long => does not match long object name
@@ -275,7 +291,7 @@ TEST_F(TestLFNIndex, remove_object) {
     std::string mangled_name;
     int exists;
     const std::string object_name(1024, 'A');
-    hobject_t hoid(sobject_t(object_name, CEPH_NOSNAP));
+    ghobject_t hoid(hobject_t(sobject_t(object_name, CEPH_NOSNAP)));
 
     //
     //   PATH/AAA..._0_long => matches long object name
@@ -323,7 +339,7 @@ TEST_F(TestLFNIndex, get_mangled_name) {
   {
     std::string mangled_name;
     int exists = 666;
-    hobject_t hoid(sobject_t("ABC", CEPH_NOSNAP));
+    ghobject_t hoid(hobject_t(sobject_t("ABC", CEPH_NOSNAP)));
 
     EXPECT_EQ(0, get_mangled_name(path, hoid, &mangled_name, &exists));
     EXPECT_NE(std::string::npos, mangled_name.find("ABC__head"));
@@ -343,7 +359,7 @@ TEST_F(TestLFNIndex, get_mangled_name) {
     std::string mangled_name;
     int exists;
     const std::string object_name(1024, 'A');
-    hobject_t hoid(sobject_t(object_name, CEPH_NOSNAP));
+    ghobject_t hoid(hobject_t(sobject_t(object_name, CEPH_NOSNAP)));
 
     //
     // long version of the mangled name and no matching
diff --git a/src/tools/ceph-filestore-dump.cc b/src/tools/ceph-filestore-dump.cc
index 01a19dd74e9..b4220bae307 100644
--- a/src/tools/ceph-filestore-dump.cc
+++ b/src/tools/ceph-filestore-dump.cc
@@ -380,8 +380,8 @@ void remove_coll(ObjectStore *store, const coll_t &coll)
     OSD::make_snapmapper_oid());
   SnapMapper mapper(&driver, 0, 0, 0);
 
-  vector<hobject_t> objects;
-  hobject_t next;
+  vector<ghobject_t> objects;
+  ghobject_t next;
   int r = 0;
   int64_t num = 0;
   ObjectStore::Transaction *t = new ObjectStore::Transaction;
@@ -391,13 +391,14 @@ void remove_coll(ObjectStore *store, const coll_t &coll)
       &objects, &next);
     if (r < 0)
       goto out;
-    for (vector<hobject_t>::iterator i = objects.begin();
+    for (vector<ghobject_t>::iterator i = objects.begin();
 	 i != objects.end();
 	 ++i, ++num) {
 
+      assert(i->generation == ghobject_t::NO_GEN);
       OSDriver::OSTransaction _t(driver.get_transaction(t));
       cout << "remove " << *i << std::endl;
-      int r = mapper.remove_oid(*i, &_t);
+      int r = mapper.remove_oid(i->hobj, &_t);
       if (r != 0 && r != -ENOENT) {
         assert(0);
       }
@@ -654,18 +655,19 @@ int export_file(ObjectStore *store, coll_t cid, hobject_t &obj)
 
 int export_files(ObjectStore *store, coll_t coll)
 {
-  vector<hobject_t> objects;
-  hobject_t next;
+  vector<ghobject_t> objects;
+  ghobject_t next;
 
   while (!next.is_max()) {
     int r = store->collection_list_partial(coll, next, 200, 300, 0,
       &objects, &next);
     if (r < 0)
       return r;
-    for (vector<hobject_t>::iterator i = objects.begin();
+    for (vector<ghobject_t>::iterator i = objects.begin();
 	 i != objects.end();
 	 ++i) {
-      r = export_file(store, coll, *i);
+      assert(i->generation == ghobject_t::NO_GEN);
+      r = export_file(store, coll, i->hobj);
       if (r < 0)
         return r;
     }
diff --git a/src/tools/ceph-osdomap-tool.cc b/src/tools/ceph-osdomap-tool.cc
index aedc4c824e7..bde4b28b45f 100644
--- a/src/tools/ceph-osdomap-tool.cc
+++ b/src/tools/ceph-osdomap-tool.cc
@@ -115,30 +115,30 @@ int main(int argc, char **argv) {
       i->value().hexdump(std::cout);
     }
   } else if (cmd == "dump-objects") {
-    vector<hobject_t> objects;
+    vector<ghobject_t> objects;
     r = omap.list_objects(&objects);
     if (r < 0) {
       std::cerr << "list_objects got: " << cpp_strerror(r) << std::endl;
       goto done;
     }
-    for (vector<hobject_t>::iterator i = objects.begin();
+    for (vector<ghobject_t>::iterator i = objects.begin();
 	 i != objects.end();
 	 ++i) {
       std::cout << *i << std::endl;
     }
     r = 0;
   } else if (cmd == "dump-objects-with-keys") {
-    vector<hobject_t> objects;
+    vector<ghobject_t> objects;
     r = omap.list_objects(&objects);
     if (r < 0) {
       std::cerr << "list_objects got: " << cpp_strerror(r) << std::endl;
       goto done;
     }
-    for (vector<hobject_t>::iterator i = objects.begin();
+    for (vector<ghobject_t>::iterator i = objects.begin();
 	 i != objects.end();
 	 ++i) {
       std::cout << "Object: " << *i << std::endl;
-      ObjectMap::ObjectMapIterator j = omap.get_iterator(*i);
+      ObjectMap::ObjectMapIterator j = omap.get_iterator(i->hobj);
       for (j->seek_to_first(); j->valid(); j->next()) {
 	std::cout << j->key() << std::endl;
 	j->value().hexdump(std::cout);
diff --git a/src/tools/dupstore.cc b/src/tools/dupstore.cc
index e17eb2201a7..c8b8ece31c8 100644
--- a/src/tools/dupstore.cc
+++ b/src/tools/dupstore.cc
@@ -27,7 +27,7 @@ int dupstore(ObjectStore* src, ObjectStore* dst)
   if (dst->mount() < 0) return 1;
 
   // objects
-  hash_map<hobject_t, coll_t> did_object;
+  hash_map<ghobject_t, coll_t> did_object;
 
   // collections
   vector<coll_t> collections;
@@ -54,11 +54,11 @@ int dupstore(ObjectStore* src, ObjectStore* dst)
       dst->apply_transaction(t);
     }
 
-    vector<hobject_t> o;
+    vector<ghobject_t> o;
     src->collection_list(*p, o);
     int numo = o.size();
     int j = 1;
-    for (vector<hobject_t>::iterator q = o.begin(); q != o.end(); ++q) {
+    for (vector<ghobject_t>::iterator q = o.begin(); q != o.end(); ++q) {
       ObjectStore::Transaction t;
       if (did_object.count(*q))
 	t.collection_add(*p, did_object[*q], *q);