Create a gist now

Instantly share code, notes, and snippets.

What would you like to do?
#!/usr/bin/python
# NOTE: We need the system wide Python(2.6) because that's where
# the guestfs libs are installed (RHEL6.X)
# rpm package python-libguestfs is required for this to work
#
# yum install python-libguestfs
#
# Provide the disk image name as the only argument to this script
#
import guestfs
import sys, string
assert (len (sys.argv) == 2)
disk = sys.argv[1]
# For return values we want a dict object
g = guestfs.GuestFS (python_return_dict=True)
# Add our image
g.add_drive_opts (disk)
# Launch the guestfs back-end (same as run)
g.launch()
# Ask libguestfs to inspect for operating systems.
roots = g.inspect_os()
if len(roots) == 0:
raise (Error ("inspect_vm: no operating systems found"))
# We should get one device back, likely /dev/sda
devs = g.list_devices()
if len(devs) == 1:
dev = devs[0]
print "Found one device: %s" % dev
else:
print "Found more than one dev, please specify which one you want to operate on.."
sys.exit(1)
# We are expecting 2 partitions back from this device
# 1st part is boot partition
# 2nd part is pvs with root.fs and swap.vol in it
partitions = g.part_list(dev)
if len(partitions) == 2:
print "Found 2 partitions"
# double check that 2nd part is actually #2 and get it's start location
if partitions[1]['part_num'] == 2:
part_start = partitions[1]['part_start']
dev_part = dev + str(partitions[1]['part_num'])
else:
print "cant find 2nd partition to modify.."
sys.exit(2)
else:
print "expected 2 partitions found %i instead" % len(partitions)
# Get block size
blk_size = g.blockdev_getss(dev)
print "Block size: %i" % blk_size
# Calculate start sector
start_sector = part_start / blk_size
print "Caclulated start sector: %i" % start_sector
# Delete 2nd partition on image
if g.part_del(dev, 2):
print "Parition delete failed.. Exiting"
sys.exit(3)
print "Old partition removed"
# Flush device
print "Flushing buffers.."
g.blockdev_flushbufs(dev)
# Recreate 2nd partition -1 means last sector
# NOTE: This command will issue a warning about the kernel failing to re-read the part table, this is ok and expected
# Actually it returns -1 even though it succeeds
try:
g.part_add(dev, 'p', start_sector, -1)
except RuntimeError as msg:
print "Part add failed due to re-read of partition table, this is normal and expected.. Ignored.."
print "Partition created/expanded"
# Shutdown and restart guestfs to get our newly expanded partition table to be seen
print "Restarting guestfs (this takes a second)"
g.shutdown()
g.add_drive_opts(disk)
g.launch()
# Resize the PV
if g.pvresize(dev_part):
print "pvresize failed.. Exiting"
sys.exit(5)
print "pv resized"
# Find and resize our volumes now
vols = g.lvs()
for vol in vols:
if string.find(string.split(vol, '/')[-1], "root.fs") >= 0:
print "root vol is: %s" % vol
root_vol = vol
if string.find(string.split(vol, '/')[-1], "swap.vol") >= 0:
print "swap vol is: %s" % vol
swap_vol = vol
if g.lvresize(swap_vol, 6144):
print "lvresize on swap failed.. Exiting"
sys.exit(6)
print "lvresize on swap succeeded"
if g.lvresize_free(root_vol, 100):
print "lvresize on root failed.. Exiting"
sys.exit(7)
print "lvresize on root succeeded"
if g.resize2fs(root_vol):
print "resize2fs on root vol failed.. Exiting"
sys.exit(8)
print "resize2fs on root succeeded"
if g.e2fsck(root_vol, correct=True):
print "e2fsck on root vol failed.. Exiting"
sys.exit(9)
print "e2fsck on root succeeded"
print "Resize completed, go ahead and boot the vm now"
g.shutdown()
g.close()
sys.exit(0)
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment