aif-ng/aif/disk/mdadm.py

141 lines
5.0 KiB
Python

import copy
import math
import re
import subprocess
##
import mdstat
##
from aif.disk.block import Disk
from aif.disk.block import Partition
SUPPORTED_LEVELS = (0, 1, 4, 5, 6)
SUPPORTED_METADATA = ('0', '0.90', '1', '1.0', '1.1', '1.2', 'default', 'ddf', 'imsm')
SUPPORTED_LAYOUTS = {5: (re.compile(r'^((left|right)-a?symmetric|[lr][as]|'
r'parity-(fir|la)st|'
r'ddf-(N|zero)-restart|ddf-N-continue)$'),
'left-symmetric'),
6: (re.compile(r'^((left|right)-a?symmetric(-6)?|[lr][as]|'
r'parity-(fir|la)st|'
r'ddf-(N|zero)-restart|ddf-N-continue|'
r'parity-first-6)$'),
None),
10: (re.compile(r'^[nof][0-9]+$'),
None)}
def _itTakesTwo(n):
# So dumb.
isPowerOf2 = math.ceil(math.log(n, 2)) == math.floor(math.log(n, 2))
return(isPowerOf2)
def _safeChunks(n):
if (n % 4) != 0:
return(False)
return(True)
class Member(object):
def __init__(self, member_xml, partobj):
self.xml = member_xml
self.device = partobj
if not isinstance(self.device, (Partition, Disk, Array)):
raise ValueError(('partobj must be of type aif.disk.block.Partition, '
'aif.disk.block.Disk, or aif.disk.mdadm.Array'))
self.devpath = self.device.devpath
def prepare(self):
# TODO: logging
subprocess.run(['mdadm', '--misc', '--zero-superblock', self.devpath])
return()
class Array(object):
def __init__(self, array_xml, homehost):
self.xml = array_xml
self.id = array_xml.attrib['id']
self.level = int(self.xml.attrib['level'])
if self.level not in SUPPORTED_LEVELS:
raise ValueError('RAID level must be one of: {0}'.format(', '.join([str(i) for i in SUPPORTED_LEVELS])))
self.metadata = self.xml.attrib.get('meta', '1.2')
if self.metadata not in SUPPORTED_METADATA:
raise ValueError('Metadata version must be one of: {0}'.format(', '.join(SUPPORTED_METADATA)))
self.chunksize = int(self.xml.attrib.get('chunkSize', 512))
if self.level in (4, 5, 6, 10):
if not _itTakesTwo(self.chunksize):
# TODO: log.warn instead of raise exception? Will mdadm lose its marbles if it *isn't* a proper number?
raise ValueError('chunksize must be a power of 2 for the RAID level you specified')
if self.level in (0, 4, 5, 6, 10):
if not _safeChunks(self.chunksize):
# TODO: log.warn instead of raise exception? Will mdadm lose its marbles if it *isn't* a proper number?
raise ValueError('chunksize must be divisible by 4 for the RAID level you specified')
self.layout = self.xml.attrib.get('layout', 'none')
if self.level in SUPPORTED_LAYOUTS.keys():
matcher, layout_default = SUPPORTED_LAYOUTS[self.level]
if not matcher.search(self.layout):
if layout_default:
self.layout = layout_default
else:
self.layout = None # TODO: log.warn?
else:
self.layout = None
self.devname = self.xml.attrib['name']
self.devpath = '/dev/md/{0}'.format(self.devname)
self.updateStatus()
self.members = []
self.state = None
def addMember(self, memberobj):
if not isinstance(memberobj, Member):
raise ValueError('memberobj must be of type aif.disk.mdadm.Member')
pass
return()
def assemble(self, scan = False):
cmd = ['mdadm', '--assemble', self.devpath]
if not scan:
for m in self.members:
cmd.append(m.devpath)
else:
cmd.extend([''])
# TODO: logging!
subprocess.run(cmd)
pass
return()
def create(self):
if not self.members:
raise RuntimeError('Cannot create an array with no members')
cmd = ['mdadm', '--create',
'--level={0}'.format(self.level),
'--metadata={0}'.format(self.metadata),
'--chunk={0}'.format(self.chunksize),
'--raid-devices={0}'.format(len(self.members))]
if self.layout:
cmd.append('--layout={0}'.format(self.layout))
cmd.append(self.devpath)
for m in self.members:
cmd.append(m.devpath)
# TODO: logging!
subprocess.run(cmd)
pass
return()
def stop(self):
# TODO: logging
subprocess.run(['mdadm', '--stop', self.devpath])
return()
def updateStatus(self):
_info = mdstat.parse()
for k, v in _info['devices'].items():
if k != self.devname:
del(_info['devices'][k])
self.info = copy.deepcopy(_info)
return()
def writeConf(self, conf = '/etc/mdadm.conf'):
pass