qubes-installer-qubes-os/storage/devicelibs/mdraid.py
2011-01-18 04:24:57 -05:00

237 lines
6.9 KiB
Python

#
# mdraid.py
# mdraid functions
#
# Copyright (C) 2009 Red Hat, Inc. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# Author(s): Dave Lehman <dlehman@redhat.com>
#
import os
import iutil
from ..errors import *
import gettext
_ = lambda x: gettext.ldgettext("anaconda", x)
import logging
log = logging.getLogger("storage")
# raidlevels constants
RAID10 = 10
RAID6 = 6
RAID5 = 5
RAID4 = 4
RAID1 = 1
RAID0 = 0
def getRaidLevels():
mdstat_descriptors = {
RAID10: ("[RAID10]", "[raid10]"),
RAID6: ("[RAID6]", "[raid6]"),
RAID5: ("[RAID5]", "[raid5]"),
RAID4: ("[RAID4]", "[raid4]"),
RAID1: ("[RAID1]", "[raid1]"),
RAID0: ("[RAID0]", "[raid0]"),
}
avail = []
try:
f = open("/proc/mdstat", "r")
except IOError:
pass
else:
for l in f.readlines():
if not l.startswith("Personalities"):
continue
lst = l.split()
for level in mdstat_descriptors:
for d in mdstat_descriptors[level]:
if d in lst:
avail.append(level)
break
f.close()
avail.sort()
return avail
raid_levels = getRaidLevels()
def raidLevel(descriptor):
for level in raid_levels:
if isRaid(level, descriptor):
return level
else:
raise ValueError, "invalid raid level descriptor %s" % descriptor
def isRaid(raid, raidlevel):
"""Return whether raidlevel is a valid descriptor of raid"""
raid_descriptors = {RAID10: ("RAID10", "raid10", "10", 10),
RAID6: ("RAID6", "raid6", "6", 6),
RAID5: ("RAID5", "raid5", "5", 5),
RAID4: ("RAID4", "raid4", "4", 4),
RAID1: ("mirror", "RAID1", "raid1", "1", 1),
RAID0: ("stripe", "RAID0", "raid0", "0", 0)}
if raid in raid_descriptors:
return raidlevel in raid_descriptors[raid]
else:
raise ValueError, "invalid raid level %d" % raid
def get_raid_min_members(raidlevel):
"""Return the minimum number of raid members required for raid level"""
raid_min_members = {RAID10: 2,
RAID6: 4,
RAID5: 3,
RAID4: 3,
RAID1: 2,
RAID0: 2}
for raid, min_members in raid_min_members.items():
if isRaid(raid, raidlevel):
return min_members
raise ValueError, "invalid raid level %d" % raidlevel
def get_raid_max_spares(raidlevel, nummembers):
"""Return the maximum number of raid spares for raidlevel."""
raid_max_spares = {RAID10: lambda: max(0, nummembers - get_raid_min_members(RAID10)),
RAID6: lambda: max(0, nummembers - get_raid_min_members(RAID6)),
RAID5: lambda: max(0, nummembers - get_raid_min_members(RAID5)),
RAID4: lambda: max(0, nummembers - get_raid_min_members(RAID4)),
RAID1: lambda: max(0, nummembers - get_raid_min_members(RAID1)),
RAID0: lambda: 0}
for raid, max_spares_func in raid_max_spares.items():
if isRaid(raid, raidlevel):
return max_spares_func()
raise ValueError, "invalid raid level %d" % raidlevel
def mdadm(args, progress=None):
rc = iutil.execWithPulseProgress("mdadm", args,
stdout = "/dev/tty5",
stderr = "/dev/tty5",
progress=progress)
if not rc:
return
try:
# grab the last line of program.log and strip off the timestamp
msg = open("/tmp/program.log").readlines()[-1]
msg = msg.split("program: ", 1)[1].strip()
except Exception:
msg = ""
raise MDRaidError(msg)
def mdcreate(device, level, disks, spares=0, metadataVer=None, bitmap=False,
progress=None):
argv = ["--create", device, "--run", "--level=%s" % level]
raid_devs = len(disks) - spares
argv.append("--raid-devices=%d" % raid_devs)
if spares:
argv.append("--spare-devices=%d" % spares)
if metadataVer:
argv.append("--metadata=%s" % metadataVer)
if bitmap:
argv.append("--bitmap=internal")
argv.extend(disks)
try:
mdadm(argv, progress=progress)
except MDRaidError as msg:
raise MDRaidError("mdcreate failed for %s: %s" % (device, msg))
def mddestroy(device):
args = ["--zero-superblock", device]
try:
mdadm(args)
except MDRaidError as msg:
raise MDRaidError("mddestroy failed for %s: %s" % (device, msg))
def mdadd(device, no_degraded=False):
args = ["--incremental", "--quiet"]
if no_degraded:
args.append("--no-degraded")
args.append(device)
try:
mdadm(args)
except MDRaidError as msg:
raise MDRaidError("mdadd failed for %s: %s" % (device, msg))
def mdactivate(device, members=[], super_minor=None, update_super_minor=False,
uuid=None):
if super_minor is None and not uuid:
raise ValueError("mdactivate requires either a uuid or a super-minor")
if uuid:
identifier = "--uuid=%s" % uuid
elif super_minor is not None:
identifier = "--super-minor=%d" % super_minor
else:
identifier = ""
if update_super_minor:
extra_args = ["--update=super-minor"]
else:
extra_args = [ ]
args = ["--assemble", device, identifier, "--run", "--auto=md"]
args += extra_args
args += members
try:
mdadm(args)
except MDRaidError as msg:
raise MDRaidError("mdactivate failed for %s: %s" % (device, msg))
def mddeactivate(device):
args = ["--stop", device]
try:
mdadm(args)
except MDRaidError as msg:
raise MDRaidError("mddeactivate failed for %s: %s" % (device, msg))
def mdexamine(device):
vars = iutil.execWithCapture("mdadm",
["--examine", "--brief", device],
stderr="/dev/tty5").split()
info = {}
if vars:
try:
info["device"] = vars[1]
vars = vars[2:]
except IndexError:
return {}
for var in vars:
(name, equals, value) = var.partition("=")
if not equals:
continue
info[name.lower()] = value.strip()
return info