Create partition at max msdos limit for disks > 2TB

Currently there is a problem on partition creation for MBR
case. If disk exceeds 2TB, partition creation fails because
we are hitting max msdos limit. Detect total disk size, and if
it exceeds that limit, create the partition at the end of legal
limits.

Fixes-Bug: #1517077
Change-Id: I11dd3f11eaa6af764151b442768d10289ced6d3f

1 files changed, 14 insertions, 2 deletions

diff --git a/ironic_python_agent/shell/copy_configdrive_to_disk.sh b/ironic_python_agent/shell/copy_configdrive_to_disk.sh
index 8b74e29d..ee4ed703 100755
--- a/ironic_python_agent/shell/copy_configdrive_to_disk.sh
+++ b/ironic_python_agent/shell/copy_configdrive_to_disk.sh
@@ -36,6 +36,7 @@ usage() {
 }
 
 MAX_DISK_PARTITIONS=128
+MAX_MBR_SIZE_MB=2097152
 
 CONFIGDRIVE="$1"
 DEVICE="$2"
@@ -86,9 +87,20 @@ else
   else
     log "Working on MBR only device $DEVICE"
 
-    # Create small partition at the end of the device
+    # get total disk size, to detect if that exceeds 2TB msdos limit
+    disksize_bytes=$(blockdev --getsize64 $DEVICE)
+    disksize_mb=$(( ${disksize_bytes%% *} / 1024 / 1024))
+
+    startlimit=-64MiB
+    endlimit=-0
+    if [ "$disksize_mb" -gt "$MAX_MBR_SIZE_MB" ]; then
+      # Create small partition at 2TB limit
+      startlimit=$(($MAX_MBR_SIZE_MB - 65))
+      endlimit=$(($MAX_MBR_SIZE_MB - 1))
+    fi
+
     log "Adding configdrive partition to $DEVICE"
-    parted -a optimal -s -- $DEVICE mkpart primary ext2 -64MiB -0 || fail "creating configdrive on ${DEVICE}"
+    parted -a optimal -s -- $DEVICE mkpart primary ext2 $startlimit $endlimit || fail "creating configdrive on ${DEVICE}"
 
     # Find partition we just created
     # Dump all partitions, ignore empty ones, then get the last partition ID