nova/nova/virt/libvirt/storage/lvm.py

194 lines
6.5 KiB
Python

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
# Copyright (c) 2010 Citrix Systems, Inc.
# Copyright (c) 2011 Piston Cloud Computing, Inc
# Copyright (c) 2011 OpenStack Foundation
# (c) Copyright 2013 Hewlett-Packard Development Company, L.P.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
import os
from oslo_concurrency import processutils
from oslo_log import log as logging
from oslo_utils import units
import six
import nova.conf
from nova import exception
from nova.i18n import _
import nova.privsep.fs
CONF = nova.conf.CONF
LOG = logging.getLogger(__name__)
# TODO(sbauza): Remove the possibility to ask for a sparse LV.
def create_volume(vg, lv, size, sparse=False):
"""Create LVM image.
Creates a LVM image with given size.
:param vg: existing volume group which should hold this image
:param lv: name for this image (logical volume)
:size: size of image in bytes
:sparse: create sparse logical volume
"""
vg_info = get_volume_group_info(vg)
free_space = vg_info['free']
def check_size(vg, lv, size):
if size > free_space:
raise RuntimeError(_('Insufficient Space on Volume Group %(vg)s.'
' Only %(free_space)db available,'
' but %(size)d bytes required'
' by volume %(lv)s.') %
{'vg': vg,
'free_space': free_space,
'size': size,
'lv': lv})
if sparse:
preallocated_space = 64 * units.Mi
check_size(vg, lv, preallocated_space)
if free_space < size:
LOG.warning('Volume group %(vg)s will not be able'
' to hold sparse volume %(lv)s.'
' Virtual volume size is %(size)d bytes,'
' but free space on volume group is'
' only %(free_space)db.',
{'vg': vg,
'free_space': free_space,
'size': size,
'lv': lv})
nova.privsep.fs.lvcreate(size, lv, vg,
preallocated=preallocated_space)
else:
check_size(vg, lv, size)
nova.privsep.fs.lvcreate(size, lv, vg)
def get_volume_group_info(vg):
"""Return free/used/total space info for a volume group in bytes
:param vg: volume group name
:returns: A dict containing:
:total: How big the filesystem is (in bytes)
:free: How much space is free (in bytes)
:used: How much space is used (in bytes)
"""
out, err = nova.privsep.fs.vginfo(vg)
info = out.split('|')
if len(info) != 2:
raise RuntimeError(_("vg %s must be LVM volume group") % vg)
return {'total': int(info[0]),
'free': int(info[1]),
'used': int(info[0]) - int(info[1])}
def list_volumes(vg):
"""List logical volumes paths for given volume group.
:param vg: volume group name
:returns: Return a logical volume list for given volume group
: Data format example
: ['volume-aaa', 'volume-bbb', 'volume-ccc']
"""
out, err = nova.privsep.fs.lvlist(vg)
return [line.strip() for line in out.splitlines()]
def volume_info(path):
"""Get logical volume info.
:param path: logical volume path
:returns: Return a dict object including info of given logical volume
: Data format example
: {'#Seg': '1', 'Move': '', 'Log': '', 'Meta%': '', 'Min': '-1',
: ...
: 'Free': '9983', 'LV': 'volume-aaa', 'Host': 'xyz.com',
: 'Active': 'active', 'Path': '/dev/vg/volume-aaa', '#LV': '3',
: 'Maj': '-1', 'VSize': '50.00g', 'VFree': '39.00g', 'Pool': '',
: 'VG Tags': '', 'KMaj': '253', 'Convert': '', 'LProfile': '',
: '#Ext': '12799', 'Attr': '-wi-a-----', 'VG': 'vg',
: ...
: 'LSize': '1.00g', '#PV': '1', '#VMdaCps': 'unmanaged'}
"""
out, err = nova.privsep.fs.lvinfo(path)
info = [line.split('|') for line in out.splitlines()]
if len(info) != 2:
raise RuntimeError(_("Path %s must be LVM logical volume") % path)
return dict(zip(*info))
def get_volume_size(path):
"""Get logical volume size in bytes.
:param path: logical volume path
:raises: processutils.ProcessExecutionError if getting the volume size
fails in some unexpected way.
:raises: exception.VolumeBDMPathNotFound if the volume path does not exist.
"""
try:
out, _err = nova.privsep.fs.blockdev_size(path)
except processutils.ProcessExecutionError:
if not os.path.exists(path):
raise exception.VolumeBDMPathNotFound(path=path)
else:
raise
return int(out)
def clear_volume(path):
"""Obfuscate the logical volume.
:param path: logical volume path
"""
if CONF.libvirt.volume_clear == 'none':
return
volume_clear_size = int(CONF.libvirt.volume_clear_size) * units.Mi
try:
volume_size = get_volume_size(path)
except exception.VolumeBDMPathNotFound:
LOG.warning('Ignoring missing logical volume %(path)s', {'path': path})
return
if volume_clear_size != 0 and volume_clear_size < volume_size:
volume_size = volume_clear_size
nova.privsep.fs.clear(path, volume_size,
shred=(CONF.libvirt.volume_clear == 'shred'))
def remove_volumes(paths):
"""Remove one or more logical volume."""
errors = []
for path in paths:
clear_volume(path)
try:
nova.privsep.fs.lvremove(path)
except processutils.ProcessExecutionError as exp:
errors.append(six.text_type(exp))
if errors:
raise exception.VolumesNotRemoved(reason=(', ').join(errors))