charm-neutron-openvswitch/hooks/charmhelpers/contrib/storage/linux/lvm.py
2015-01-26 09:42:44 +00:00

106 lines
3.0 KiB
Python

# Copyright 2014-2015 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
from subprocess import (
CalledProcessError,
check_call,
check_output,
Popen,
PIPE,
)
##################################################
# LVM helpers.
##################################################
def deactivate_lvm_volume_group(block_device):
'''
Deactivate any volume gruop associated with an LVM physical volume.
:param block_device: str: Full path to LVM physical volume
'''
vg = list_lvm_volume_group(block_device)
if vg:
cmd = ['vgchange', '-an', vg]
check_call(cmd)
def is_lvm_physical_volume(block_device):
'''
Determine whether a block device is initialized as an LVM PV.
:param block_device: str: Full path of block device to inspect.
:returns: boolean: True if block device is a PV, False if not.
'''
try:
check_output(['pvdisplay', block_device])
return True
except CalledProcessError:
return False
def remove_lvm_physical_volume(block_device):
'''
Remove LVM PV signatures from a given block device.
:param block_device: str: Full path of block device to scrub.
'''
p = Popen(['pvremove', '-ff', block_device],
stdin=PIPE)
p.communicate(input='y\n')
def list_lvm_volume_group(block_device):
'''
List LVM volume group associated with a given block device.
Assumes block device is a valid LVM PV.
:param block_device: str: Full path of block device to inspect.
:returns: str: Name of volume group associated with block device or None
'''
vg = None
pvd = check_output(['pvdisplay', block_device]).splitlines()
for l in pvd:
l = l.decode('UTF-8')
if l.strip().startswith('VG Name'):
vg = ' '.join(l.strip().split()[2:])
return vg
def create_lvm_physical_volume(block_device):
'''
Initialize a block device as an LVM physical volume.
:param block_device: str: Full path of block device to initialize.
'''
check_call(['pvcreate', block_device])
def create_lvm_volume_group(volume_group, block_device):
'''
Create an LVM volume group backed by a given block device.
Assumes block device has already been initialized as an LVM PV.
:param volume_group: str: Name of volume group to create.
:block_device: str: Full path of PV-initialized block device.
'''
check_call(['vgcreate', volume_group, block_device])