root / lib / storage / drbd.py @ 653bc0f1
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# Copyright (C) 2006, 2007, 2010, 2011, 2012, 2013 Google Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""DRBD block device related functionality"""
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import errno |
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import logging |
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import time |
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from ganeti import constants |
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from ganeti import utils |
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from ganeti import errors |
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from ganeti import netutils |
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from ganeti import objects |
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from ganeti.storage import base |
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from ganeti.storage.drbd_info import DRBD8Info |
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from ganeti.storage import drbd_info |
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from ganeti.storage import drbd_cmdgen |
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# Size of reads in _CanReadDevice
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_DEVICE_READ_SIZE = 128 * 1024 |
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class DRBD8(object): |
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"""Various methods to deals with the DRBD system as a whole.
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This class provides a set of methods to deal with the DRBD installation on
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the node or with uninitialized devices as opposed to a DRBD device.
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"""
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_USERMODE_HELPER_FILE = "/sys/module/drbd/parameters/usermode_helper"
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_MAX_MINORS = 255
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@staticmethod
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def GetUsermodeHelper(filename=_USERMODE_HELPER_FILE): |
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"""Returns DRBD usermode_helper currently set.
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@type filename: string
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@param filename: the filename to read the usermode helper from
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@rtype: string
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@return: the currently configured DRBD usermode helper
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"""
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try:
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helper = utils.ReadFile(filename).splitlines()[0]
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except EnvironmentError, err: |
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if err.errno == errno.ENOENT:
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base.ThrowError("The file %s cannot be opened, check if the module"
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" is loaded (%s)", filename, str(err)) |
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else:
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base.ThrowError("Can't read DRBD helper file %s: %s",
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filename, str(err))
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if not helper: |
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base.ThrowError("Can't read any data from %s", filename)
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return helper
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@staticmethod
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def GetProcInfo(): |
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"""Reads and parses information from /proc/drbd.
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@rtype: DRBD8Info
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@return: a L{DRBD8Info} instance containing the current /proc/drbd info
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"""
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return DRBD8Info.CreateFromFile()
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@staticmethod
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def GetUsedDevs(): |
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"""Compute the list of used DRBD minors.
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@rtype: list of ints
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"""
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info = DRBD8.GetProcInfo() |
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return filter(lambda m: not info.GetMinorStatus(m).is_unconfigured, |
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info.GetMinors()) |
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@staticmethod
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def FindUnusedMinor(): |
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"""Find an unused DRBD device.
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This is specific to 8.x as the minors are allocated dynamically,
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so non-existing numbers up to a max minor count are actually free.
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@rtype: int
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"""
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highest = None
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info = DRBD8.GetProcInfo() |
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for minor in info.GetMinors(): |
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status = info.GetMinorStatus(minor) |
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if not status.is_in_use: |
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return minor
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highest = max(highest, minor)
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if highest is None: # there are no minors in use at all |
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return 0 |
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if highest >= DRBD8._MAX_MINORS:
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logging.error("Error: no free drbd minors!")
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raise errors.BlockDeviceError("Can't find a free DRBD minor") |
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return highest + 1 |
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@staticmethod
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def GetCmdGenerator(info): |
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"""Creates a suitable L{BaseDRBDCmdGenerator} based on the given info.
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@type info: DRBD8Info
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@rtype: BaseDRBDCmdGenerator
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"""
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version = info.GetVersion() |
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if version["k_minor"] <= 3: |
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return drbd_cmdgen.DRBD83CmdGenerator(version)
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else:
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return drbd_cmdgen.DRBD84CmdGenerator(version)
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@staticmethod
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def ShutdownAll(minor): |
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"""Deactivate the device.
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This will, of course, fail if the device is in use.
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@type minor: int
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@param minor: the minor to shut down
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"""
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info = DRBD8.GetProcInfo() |
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cmd_gen = DRBD8.GetCmdGenerator(info) |
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cmd = cmd_gen.GenDownCmd(minor) |
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result = utils.RunCmd(cmd) |
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if result.failed:
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base.ThrowError("drbd%d: can't shutdown drbd device: %s",
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minor, result.output) |
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class DRBD8Dev(base.BlockDev): |
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"""DRBD v8.x block device.
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This implements the local host part of the DRBD device, i.e. it
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doesn't do anything to the supposed peer. If you need a fully
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connected DRBD pair, you need to use this class on both hosts.
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The unique_id for the drbd device is a (pnode_uuid, snode_uuid,
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port, pnode_minor, lnode_minor, secret) tuple, and it must have
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two children: the data device and the meta_device. The meta
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device is checked for valid size and is zeroed on create.
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"""
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_DRBD_MAJOR = 147
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# timeout constants
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_NET_RECONFIG_TIMEOUT = 60
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def __init__(self, unique_id, children, size, params, dyn_params, *args): |
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if children and children.count(None) > 0: |
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children = [] |
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if len(children) not in (0, 2): |
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raise ValueError("Invalid configuration data %s" % str(children)) |
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if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 6: |
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raise ValueError("Invalid configuration data %s" % str(unique_id)) |
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if constants.DDP_LOCAL_IP not in dyn_params or \ |
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constants.DDP_REMOTE_IP not in dyn_params or \ |
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constants.DDP_LOCAL_MINOR not in dyn_params or \ |
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constants.DDP_REMOTE_MINOR not in dyn_params: |
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raise ValueError("Invalid dynamic parameters %s" % str(dyn_params)) |
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self._lhost = dyn_params[constants.DDP_LOCAL_IP]
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self._lport = unique_id[2] |
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self._rhost = dyn_params[constants.DDP_REMOTE_IP]
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self._rport = unique_id[2] |
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self._aminor = dyn_params[constants.DDP_LOCAL_MINOR]
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self._secret = unique_id[5] |
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if children:
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if not _CanReadDevice(children[1].dev_path): |
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logging.info("drbd%s: Ignoring unreadable meta device", self._aminor) |
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children = [] |
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super(DRBD8Dev, self).__init__(unique_id, children, size, params, |
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dyn_params, *args) |
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self.major = self._DRBD_MAJOR |
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info = DRBD8.GetProcInfo() |
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version = info.GetVersion() |
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if version["k_major"] != 8: |
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base.ThrowError("Mismatch in DRBD kernel version and requested ganeti"
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" usage: kernel is %s.%s, ganeti wants 8.x",
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version["k_major"], version["k_minor"]) |
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if version["k_minor"] <= 3: |
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self._show_info_cls = drbd_info.DRBD83ShowInfo
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else:
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self._show_info_cls = drbd_info.DRBD84ShowInfo
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self._cmd_gen = DRBD8.GetCmdGenerator(info)
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if (self._lhost is not None and self._lhost == self._rhost and |
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self._lport == self._rport): |
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raise ValueError("Invalid configuration data, same local/remote %s, %s" % |
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(unique_id, dyn_params)) |
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self.Attach()
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@staticmethod
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def _DevPath(minor): |
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"""Return the path to a drbd device for a given minor.
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@type minor: int
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@rtype: string
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"""
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return "/dev/drbd%d" % minor |
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def _SetFromMinor(self, minor): |
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"""Set our parameters based on the given minor.
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This sets our minor variable and our dev_path.
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@type minor: int
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"""
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if minor is None: |
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self.minor = self.dev_path = None |
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self.attached = False |
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else:
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self.minor = minor
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self.dev_path = self._DevPath(minor) |
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self.attached = True |
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@staticmethod
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def _CheckMetaSize(meta_device): |
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"""Check if the given meta device looks like a valid one.
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This currently only checks the size, which must be around
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128MiB.
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@type meta_device: string
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@param meta_device: the path to the device to check
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"""
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result = utils.RunCmd(["blockdev", "--getsize", meta_device]) |
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if result.failed:
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base.ThrowError("Failed to get device size: %s - %s",
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result.fail_reason, result.output) |
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try:
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sectors = int(result.stdout)
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except (TypeError, ValueError): |
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base.ThrowError("Invalid output from blockdev: '%s'", result.stdout)
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num_bytes = sectors * 512
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if num_bytes < 128 * 1024 * 1024: # less than 128MiB |
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base.ThrowError("Meta device too small (%.2fMib)",
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(num_bytes / 1024 / 1024)) |
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# the maximum *valid* size of the meta device when living on top
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# of LVM is hard to compute: it depends on the number of stripes
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# and the PE size; e.g. a 2-stripe, 64MB PE will result in a 128MB
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# (normal size), but an eight-stripe 128MB PE will result in a 1GB
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# size meta device; as such, we restrict it to 1GB (a little bit
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# too generous, but making assumptions about PE size is hard)
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if num_bytes > 1024 * 1024 * 1024: |
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base.ThrowError("Meta device too big (%.2fMiB)",
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(num_bytes / 1024 / 1024)) |
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def _GetShowData(self, minor): |
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"""Return the `drbdsetup show` data.
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@type minor: int
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@param minor: the minor to collect show output for
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@rtype: string
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"""
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result = utils.RunCmd(self._cmd_gen.GenShowCmd(minor))
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if result.failed:
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logging.error("Can't display the drbd config: %s - %s",
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result.fail_reason, result.output) |
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return None |
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return result.stdout
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def _GetShowInfo(self, minor): |
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"""Return parsed information from `drbdsetup show`.
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@type minor: int
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@param minor: the minor to return information for
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@rtype: dict as described in L{drbd_info.BaseShowInfo.GetDevInfo}
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"""
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return self._show_info_cls.GetDevInfo(self._GetShowData(minor)) |
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def _MatchesLocal(self, info): |
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"""Test if our local config matches with an existing device.
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The parameter should be as returned from `_GetShowInfo()`. This
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method tests if our local backing device is the same as the one in
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the info parameter, in effect testing if we look like the given
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device.
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@type info: dict as described in L{drbd_info.BaseShowInfo.GetDevInfo}
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@rtype: boolean
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"""
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if self._children: |
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backend, meta = self._children
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else:
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backend = meta = None
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if backend is not None: |
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retval = ("local_dev" in info and info["local_dev"] == backend.dev_path) |
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else:
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retval = ("local_dev" not in info) |
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if meta is not None: |
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retval = retval and ("meta_dev" in info and |
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info["meta_dev"] == meta.dev_path)
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if "meta_index" in info: |
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retval = retval and info["meta_index"] == 0 |
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else:
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retval = retval and ("meta_dev" not in info and |
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"meta_index" not in info) |
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return retval
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def _MatchesNet(self, info): |
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"""Test if our network config matches with an existing device.
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The parameter should be as returned from `_GetShowInfo()`. This
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method tests if our network configuration is the same as the one
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in the info parameter, in effect testing if we look like the given
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device.
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@type info: dict as described in L{drbd_info.BaseShowInfo.GetDevInfo}
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@rtype: boolean
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"""
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if (((self._lhost is None and not ("local_addr" in info)) and |
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(self._rhost is None and not ("remote_addr" in info)))): |
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return True |
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if self._lhost is None: |
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return False |
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if not ("local_addr" in info and |
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"remote_addr" in info): |
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return False |
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retval = (info["local_addr"] == (self._lhost, self._lport)) |
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retval = (retval and
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info["remote_addr"] == (self._rhost, self._rport)) |
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return retval
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def _AssembleLocal(self, minor, backend, meta, size): |
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"""Configure the local part of a DRBD device.
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@type minor: int
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@param minor: the minor to assemble locally
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@type backend: string
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@param backend: path to the data device to use
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@type meta: string
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@param meta: path to the meta device to use
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@type size: int
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@param size: size in MiB
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"""
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cmds = self._cmd_gen.GenLocalInitCmds(minor, backend, meta,
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size, self.params)
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for cmd in cmds: |
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result = utils.RunCmd(cmd) |
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if result.failed:
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base.ThrowError("drbd%d: can't attach local disk: %s",
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minor, result.output) |
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def _AssembleNet(self, minor, net_info, dual_pri=False, hmac=None, |
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secret=None):
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"""Configure the network part of the device.
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@type minor: int
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@param minor: the minor to assemble the network for
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@type net_info: (string, int, string, int)
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@param net_info: tuple containing the local address, local port, remote
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address and remote port
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@type dual_pri: boolean
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@param dual_pri: whether two primaries should be allowed or not
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@type hmac: string
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@param hmac: the HMAC algorithm to use
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@type secret: string
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@param secret: the shared secret to use
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"""
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lhost, lport, rhost, rport = net_info |
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if None in net_info: |
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# we don't want network connection and actually want to make
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# sure its shutdown
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self._ShutdownNet(minor)
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return
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if dual_pri:
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protocol = constants.DRBD_MIGRATION_NET_PROTOCOL |
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else:
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protocol = self.params[constants.LDP_PROTOCOL]
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# Workaround for a race condition. When DRBD is doing its dance to
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# establish a connection with its peer, it also sends the
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# synchronization speed over the wire. In some cases setting the
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# sync speed only after setting up both sides can race with DRBD
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# connecting, hence we set it here before telling DRBD anything
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# about its peer.
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sync_errors = self._SetMinorSyncParams(minor, self.params) |
427 |
if sync_errors:
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base.ThrowError("drbd%d: can't set the synchronization parameters: %s" %
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(minor, utils.CommaJoin(sync_errors))) |
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family = self._GetNetFamily(minor, lhost, rhost)
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cmd = self._cmd_gen.GenNetInitCmd(minor, family, lhost, lport,
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rhost, rport, protocol, |
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dual_pri, hmac, secret, self.params)
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result = utils.RunCmd(cmd) |
438 |
if result.failed:
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base.ThrowError("drbd%d: can't setup network: %s - %s",
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minor, result.fail_reason, result.output) |
441 |
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def _CheckNetworkConfig(): |
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info = self._GetShowInfo(minor)
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if not "local_addr" in info or not "remote_addr" in info: |
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raise utils.RetryAgain()
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if (info["local_addr"] != (lhost, lport) or |
448 |
info["remote_addr"] != (rhost, rport)):
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raise utils.RetryAgain()
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try:
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utils.Retry(_CheckNetworkConfig, 1.0, 10.0) |
453 |
except utils.RetryTimeout:
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base.ThrowError("drbd%d: timeout while configuring network", minor)
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# Once the assembly is over, try to set the synchronization parameters
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try:
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# The minor may not have been set yet, requiring us to set it at least
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# temporarily
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old_minor = self.minor
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self._SetFromMinor(minor)
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sync_errors = self.SetSyncParams(self.params) |
463 |
if sync_errors:
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base.ThrowError("drbd%d: can't set the synchronization parameters: %s" %
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(self.minor, utils.CommaJoin(sync_errors)))
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finally:
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# Undo the change, regardless of whether it will have to be done again
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# soon
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self._SetFromMinor(old_minor)
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@staticmethod
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def _GetNetFamily(minor, lhost, rhost): |
473 |
if netutils.IP6Address.IsValid(lhost):
|
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if not netutils.IP6Address.IsValid(rhost): |
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base.ThrowError("drbd%d: can't connect ip %s to ip %s" %
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(minor, lhost, rhost)) |
477 |
return "ipv6" |
478 |
elif netutils.IP4Address.IsValid(lhost):
|
479 |
if not netutils.IP4Address.IsValid(rhost): |
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base.ThrowError("drbd%d: can't connect ip %s to ip %s" %
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(minor, lhost, rhost)) |
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return "ipv4" |
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else:
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base.ThrowError("drbd%d: Invalid ip %s" % (minor, lhost))
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|
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def AddChildren(self, devices): |
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"""Add a disk to the DRBD device.
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|
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@type devices: list of L{BlockDev}
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@param devices: a list of exactly two L{BlockDev} objects; the first
|
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denotes the data device, the second the meta device for this DRBD device
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|
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"""
|
494 |
if self.minor is None: |
495 |
base.ThrowError("drbd%d: can't attach to dbrd8 during AddChildren",
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self._aminor)
|
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if len(devices) != 2: |
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base.ThrowError("drbd%d: need two devices for AddChildren", self.minor) |
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info = self._GetShowInfo(self.minor) |
500 |
if "local_dev" in info: |
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base.ThrowError("drbd%d: already attached to a local disk", self.minor) |
502 |
backend, meta = devices |
503 |
if backend.dev_path is None or meta.dev_path is None: |
504 |
base.ThrowError("drbd%d: children not ready during AddChildren",
|
505 |
self.minor)
|
506 |
backend.Open() |
507 |
meta.Open() |
508 |
self._CheckMetaSize(meta.dev_path)
|
509 |
self._InitMeta(DRBD8.FindUnusedMinor(), meta.dev_path)
|
510 |
|
511 |
self._AssembleLocal(self.minor, backend.dev_path, meta.dev_path, self.size) |
512 |
self._children = devices
|
513 |
|
514 |
def RemoveChildren(self, devices): |
515 |
"""Detach the drbd device from local storage.
|
516 |
|
517 |
@type devices: list of L{BlockDev}
|
518 |
@param devices: a list of exactly two L{BlockDev} objects; the first
|
519 |
denotes the data device, the second the meta device for this DRBD device
|
520 |
|
521 |
"""
|
522 |
if self.minor is None: |
523 |
base.ThrowError("drbd%d: can't attach to drbd8 during RemoveChildren",
|
524 |
self._aminor)
|
525 |
# early return if we don't actually have backing storage
|
526 |
info = self._GetShowInfo(self.minor) |
527 |
if "local_dev" not in info: |
528 |
return
|
529 |
if len(self._children) != 2: |
530 |
base.ThrowError("drbd%d: we don't have two children: %s", self.minor, |
531 |
self._children)
|
532 |
if self._children.count(None) == 2: # we don't actually have children :) |
533 |
logging.warning("drbd%d: requested detach while detached", self.minor) |
534 |
return
|
535 |
if len(devices) != 2: |
536 |
base.ThrowError("drbd%d: we need two children in RemoveChildren",
|
537 |
self.minor)
|
538 |
for child, dev in zip(self._children, devices): |
539 |
if dev != child.dev_path:
|
540 |
base.ThrowError("drbd%d: mismatch in local storage (%s != %s) in"
|
541 |
" RemoveChildren", self.minor, dev, child.dev_path) |
542 |
|
543 |
self._ShutdownLocal(self.minor) |
544 |
self._children = []
|
545 |
|
546 |
def _SetMinorSyncParams(self, minor, params): |
547 |
"""Set the parameters of the DRBD syncer.
|
548 |
|
549 |
This is the low-level implementation.
|
550 |
|
551 |
@type minor: int
|
552 |
@param minor: the drbd minor whose settings we change
|
553 |
@type params: dict
|
554 |
@param params: LD level disk parameters related to the synchronization
|
555 |
@rtype: list
|
556 |
@return: a list of error messages
|
557 |
|
558 |
"""
|
559 |
cmd = self._cmd_gen.GenSyncParamsCmd(minor, params)
|
560 |
result = utils.RunCmd(cmd) |
561 |
if result.failed:
|
562 |
msg = ("Can't change syncer rate: %s - %s" %
|
563 |
(result.fail_reason, result.output)) |
564 |
logging.error(msg) |
565 |
return [msg]
|
566 |
|
567 |
return []
|
568 |
|
569 |
def SetSyncParams(self, params): |
570 |
"""Set the synchronization parameters of the DRBD syncer.
|
571 |
|
572 |
See L{BlockDev.SetSyncParams} for parameter description.
|
573 |
|
574 |
"""
|
575 |
if self.minor is None: |
576 |
err = "Not attached during SetSyncParams"
|
577 |
logging.info(err) |
578 |
return [err]
|
579 |
|
580 |
children_result = super(DRBD8Dev, self).SetSyncParams(params) |
581 |
children_result.extend(self._SetMinorSyncParams(self.minor, params)) |
582 |
return children_result
|
583 |
|
584 |
def PauseResumeSync(self, pause): |
585 |
"""Pauses or resumes the sync of a DRBD device.
|
586 |
|
587 |
See L{BlockDev.PauseResumeSync} for parameter description.
|
588 |
|
589 |
"""
|
590 |
if self.minor is None: |
591 |
logging.info("Not attached during PauseSync")
|
592 |
return False |
593 |
|
594 |
children_result = super(DRBD8Dev, self).PauseResumeSync(pause) |
595 |
|
596 |
if pause:
|
597 |
cmd = self._cmd_gen.GenPauseSyncCmd(self.minor) |
598 |
else:
|
599 |
cmd = self._cmd_gen.GenResumeSyncCmd(self.minor) |
600 |
|
601 |
result = utils.RunCmd(cmd) |
602 |
if result.failed:
|
603 |
logging.error("Can't %s: %s - %s", cmd,
|
604 |
result.fail_reason, result.output) |
605 |
return not result.failed and children_result |
606 |
|
607 |
def GetProcStatus(self): |
608 |
"""Return the current status data from /proc/drbd for this device.
|
609 |
|
610 |
@rtype: DRBD8Status
|
611 |
|
612 |
"""
|
613 |
if self.minor is None: |
614 |
base.ThrowError("drbd%d: GetStats() called while not attached",
|
615 |
self._aminor)
|
616 |
info = DRBD8.GetProcInfo() |
617 |
if not info.HasMinorStatus(self.minor): |
618 |
base.ThrowError("drbd%d: can't find myself in /proc", self.minor) |
619 |
return info.GetMinorStatus(self.minor) |
620 |
|
621 |
def GetSyncStatus(self): |
622 |
"""Returns the sync status of the device.
|
623 |
|
624 |
If sync_percent is None, it means all is ok
|
625 |
If estimated_time is None, it means we can't estimate
|
626 |
the time needed, otherwise it's the time left in seconds.
|
627 |
|
628 |
We set the is_degraded parameter to True on two conditions:
|
629 |
network not connected or local disk missing.
|
630 |
|
631 |
We compute the ldisk parameter based on whether we have a local
|
632 |
disk or not.
|
633 |
|
634 |
@rtype: objects.BlockDevStatus
|
635 |
|
636 |
"""
|
637 |
if self.minor is None and not self.Attach(): |
638 |
base.ThrowError("drbd%d: can't Attach() in GetSyncStatus", self._aminor) |
639 |
|
640 |
stats = self.GetProcStatus()
|
641 |
is_degraded = not stats.is_connected or not stats.is_disk_uptodate |
642 |
|
643 |
if stats.is_disk_uptodate:
|
644 |
ldisk_status = constants.LDS_OKAY |
645 |
elif stats.is_diskless:
|
646 |
ldisk_status = constants.LDS_FAULTY |
647 |
else:
|
648 |
ldisk_status = constants.LDS_UNKNOWN |
649 |
|
650 |
return objects.BlockDevStatus(dev_path=self.dev_path, |
651 |
major=self.major,
|
652 |
minor=self.minor,
|
653 |
sync_percent=stats.sync_percent, |
654 |
estimated_time=stats.est_time, |
655 |
is_degraded=is_degraded, |
656 |
ldisk_status=ldisk_status) |
657 |
|
658 |
def Open(self, force=False): |
659 |
"""Make the local state primary.
|
660 |
|
661 |
If the 'force' parameter is given, DRBD is instructed to switch the device
|
662 |
into primary mode. Since this is a potentially dangerous operation, the
|
663 |
force flag should be only given after creation, when it actually is
|
664 |
mandatory.
|
665 |
|
666 |
"""
|
667 |
if self.minor is None and not self.Attach(): |
668 |
logging.error("DRBD cannot attach to a device during open")
|
669 |
return False |
670 |
|
671 |
cmd = self._cmd_gen.GenPrimaryCmd(self.minor, force) |
672 |
|
673 |
result = utils.RunCmd(cmd) |
674 |
if result.failed:
|
675 |
base.ThrowError("drbd%d: can't make drbd device primary: %s", self.minor, |
676 |
result.output) |
677 |
|
678 |
def Close(self): |
679 |
"""Make the local state secondary.
|
680 |
|
681 |
This will, of course, fail if the device is in use.
|
682 |
|
683 |
"""
|
684 |
if self.minor is None and not self.Attach(): |
685 |
base.ThrowError("drbd%d: can't Attach() in Close()", self._aminor) |
686 |
cmd = self._cmd_gen.GenSecondaryCmd(self.minor) |
687 |
result = utils.RunCmd(cmd) |
688 |
if result.failed:
|
689 |
base.ThrowError("drbd%d: can't switch drbd device to secondary: %s",
|
690 |
self.minor, result.output)
|
691 |
|
692 |
def DisconnectNet(self): |
693 |
"""Removes network configuration.
|
694 |
|
695 |
This method shutdowns the network side of the device.
|
696 |
|
697 |
The method will wait up to a hardcoded timeout for the device to
|
698 |
go into standalone after the 'disconnect' command before
|
699 |
re-configuring it, as sometimes it takes a while for the
|
700 |
disconnect to actually propagate and thus we might issue a 'net'
|
701 |
command while the device is still connected. If the device will
|
702 |
still be attached to the network and we time out, we raise an
|
703 |
exception.
|
704 |
|
705 |
"""
|
706 |
if self.minor is None: |
707 |
base.ThrowError("drbd%d: disk not attached in re-attach net",
|
708 |
self._aminor)
|
709 |
|
710 |
if None in (self._lhost, self._lport, self._rhost, self._rport): |
711 |
base.ThrowError("drbd%d: DRBD disk missing network info in"
|
712 |
" DisconnectNet()", self.minor) |
713 |
|
714 |
class _DisconnectStatus: |
715 |
def __init__(self, ever_disconnected): |
716 |
self.ever_disconnected = ever_disconnected
|
717 |
|
718 |
dstatus = _DisconnectStatus(base.IgnoreError(self._ShutdownNet, self.minor)) |
719 |
|
720 |
def _WaitForDisconnect(): |
721 |
if self.GetProcStatus().is_standalone: |
722 |
return
|
723 |
|
724 |
# retry the disconnect, it seems possible that due to a well-time
|
725 |
# disconnect on the peer, my disconnect command might be ignored and
|
726 |
# forgotten
|
727 |
dstatus.ever_disconnected = \ |
728 |
base.IgnoreError(self._ShutdownNet, self.minor) or \ |
729 |
dstatus.ever_disconnected |
730 |
|
731 |
raise utils.RetryAgain()
|
732 |
|
733 |
# Keep start time
|
734 |
start_time = time.time() |
735 |
|
736 |
try:
|
737 |
# Start delay at 100 milliseconds and grow up to 2 seconds
|
738 |
utils.Retry(_WaitForDisconnect, (0.1, 1.5, 2.0), |
739 |
self._NET_RECONFIG_TIMEOUT)
|
740 |
except utils.RetryTimeout:
|
741 |
if dstatus.ever_disconnected:
|
742 |
msg = ("drbd%d: device did not react to the"
|
743 |
" 'disconnect' command in a timely manner")
|
744 |
else:
|
745 |
msg = "drbd%d: can't shutdown network, even after multiple retries"
|
746 |
|
747 |
base.ThrowError(msg, self.minor)
|
748 |
|
749 |
reconfig_time = time.time() - start_time |
750 |
if reconfig_time > (self._NET_RECONFIG_TIMEOUT * 0.25): |
751 |
logging.info("drbd%d: DisconnectNet: detach took %.3f seconds",
|
752 |
self.minor, reconfig_time)
|
753 |
|
754 |
def AttachNet(self, multimaster): |
755 |
"""Reconnects the network.
|
756 |
|
757 |
This method connects the network side of the device with a
|
758 |
specified multi-master flag. The device needs to be 'Standalone'
|
759 |
but have valid network configuration data.
|
760 |
|
761 |
@type multimaster: boolean
|
762 |
@param multimaster: init the network in dual-primary mode
|
763 |
|
764 |
"""
|
765 |
if self.minor is None: |
766 |
base.ThrowError("drbd%d: device not attached in AttachNet", self._aminor) |
767 |
|
768 |
if None in (self._lhost, self._lport, self._rhost, self._rport): |
769 |
base.ThrowError("drbd%d: missing network info in AttachNet()", self.minor) |
770 |
|
771 |
status = self.GetProcStatus()
|
772 |
|
773 |
if not status.is_standalone: |
774 |
base.ThrowError("drbd%d: device is not standalone in AttachNet",
|
775 |
self.minor)
|
776 |
|
777 |
self._AssembleNet(self.minor, |
778 |
(self._lhost, self._lport, self._rhost, self._rport), |
779 |
dual_pri=multimaster, hmac=constants.DRBD_HMAC_ALG, |
780 |
secret=self._secret)
|
781 |
|
782 |
def Attach(self): |
783 |
"""Check if our minor is configured.
|
784 |
|
785 |
This doesn't do any device configurations - it only checks if the
|
786 |
minor is in a state different from Unconfigured.
|
787 |
|
788 |
Note that this function will not change the state of the system in
|
789 |
any way (except in case of side-effects caused by reading from
|
790 |
/proc).
|
791 |
|
792 |
"""
|
793 |
used_devs = DRBD8.GetUsedDevs() |
794 |
if self._aminor in used_devs: |
795 |
minor = self._aminor
|
796 |
else:
|
797 |
minor = None
|
798 |
|
799 |
self._SetFromMinor(minor)
|
800 |
return minor is not None |
801 |
|
802 |
def Assemble(self): |
803 |
"""Assemble the drbd.
|
804 |
|
805 |
Method:
|
806 |
- if we have a configured device, we try to ensure that it matches
|
807 |
our config
|
808 |
- if not, we create it from zero
|
809 |
- anyway, set the device parameters
|
810 |
|
811 |
"""
|
812 |
super(DRBD8Dev, self).Assemble() |
813 |
|
814 |
self.Attach()
|
815 |
if self.minor is None: |
816 |
# local device completely unconfigured
|
817 |
self._FastAssemble()
|
818 |
else:
|
819 |
# we have to recheck the local and network status and try to fix
|
820 |
# the device
|
821 |
self._SlowAssemble()
|
822 |
|
823 |
def _SlowAssemble(self): |
824 |
"""Assembles the DRBD device from a (partially) configured device.
|
825 |
|
826 |
In case of partially attached (local device matches but no network
|
827 |
setup), we perform the network attach. If successful, we re-test
|
828 |
the attach if can return success.
|
829 |
|
830 |
"""
|
831 |
# TODO: Rewrite to not use a for loop just because there is 'break'
|
832 |
# pylint: disable=W0631
|
833 |
net_data = (self._lhost, self._lport, self._rhost, self._rport) |
834 |
for minor in (self._aminor,): |
835 |
info = self._GetShowInfo(minor)
|
836 |
match_l = self._MatchesLocal(info)
|
837 |
match_r = self._MatchesNet(info)
|
838 |
|
839 |
if match_l and match_r: |
840 |
# everything matches
|
841 |
break
|
842 |
|
843 |
if match_l and not match_r and "local_addr" not in info: |
844 |
# disk matches, but not attached to network, attach and recheck
|
845 |
self._AssembleNet(minor, net_data, hmac=constants.DRBD_HMAC_ALG,
|
846 |
secret=self._secret)
|
847 |
if self._MatchesNet(self._GetShowInfo(minor)): |
848 |
break
|
849 |
else:
|
850 |
base.ThrowError("drbd%d: network attach successful, but 'drbdsetup"
|
851 |
" show' disagrees", minor)
|
852 |
|
853 |
if match_r and "local_dev" not in info: |
854 |
# no local disk, but network attached and it matches
|
855 |
self._AssembleLocal(minor, self._children[0].dev_path, |
856 |
self._children[1].dev_path, self.size) |
857 |
if self._MatchesLocal(self._GetShowInfo(minor)): |
858 |
break
|
859 |
else:
|
860 |
base.ThrowError("drbd%d: disk attach successful, but 'drbdsetup"
|
861 |
" show' disagrees", minor)
|
862 |
|
863 |
# this case must be considered only if we actually have local
|
864 |
# storage, i.e. not in diskless mode, because all diskless
|
865 |
# devices are equal from the point of view of local
|
866 |
# configuration
|
867 |
if (match_l and "local_dev" in info and |
868 |
not match_r and "local_addr" in info): |
869 |
# strange case - the device network part points to somewhere
|
870 |
# else, even though its local storage is ours; as we own the
|
871 |
# drbd space, we try to disconnect from the remote peer and
|
872 |
# reconnect to our correct one
|
873 |
try:
|
874 |
self._ShutdownNet(minor)
|
875 |
except errors.BlockDeviceError, err:
|
876 |
base.ThrowError("drbd%d: device has correct local storage, wrong"
|
877 |
" remote peer and is unable to disconnect in order"
|
878 |
" to attach to the correct peer: %s", minor, str(err)) |
879 |
# note: _AssembleNet also handles the case when we don't want
|
880 |
# local storage (i.e. one or more of the _[lr](host|port) is
|
881 |
# None)
|
882 |
self._AssembleNet(minor, net_data, hmac=constants.DRBD_HMAC_ALG,
|
883 |
secret=self._secret)
|
884 |
if self._MatchesNet(self._GetShowInfo(minor)): |
885 |
break
|
886 |
else:
|
887 |
base.ThrowError("drbd%d: network attach successful, but 'drbdsetup"
|
888 |
" show' disagrees", minor)
|
889 |
|
890 |
else:
|
891 |
minor = None
|
892 |
|
893 |
self._SetFromMinor(minor)
|
894 |
if minor is None: |
895 |
base.ThrowError("drbd%d: cannot activate, unknown or unhandled reason",
|
896 |
self._aminor)
|
897 |
|
898 |
def _FastAssemble(self): |
899 |
"""Assemble the drbd device from zero.
|
900 |
|
901 |
This is run when in Assemble we detect our minor is unused.
|
902 |
|
903 |
"""
|
904 |
minor = self._aminor
|
905 |
if self._children and self._children[0] and self._children[1]: |
906 |
self._AssembleLocal(minor, self._children[0].dev_path, |
907 |
self._children[1].dev_path, self.size) |
908 |
if self._lhost and self._lport and self._rhost and self._rport: |
909 |
self._AssembleNet(minor,
|
910 |
(self._lhost, self._lport, self._rhost, self._rport), |
911 |
hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
|
912 |
self._SetFromMinor(minor)
|
913 |
|
914 |
def _ShutdownLocal(self, minor): |
915 |
"""Detach from the local device.
|
916 |
|
917 |
I/Os will continue to be served from the remote device. If we
|
918 |
don't have a remote device, this operation will fail.
|
919 |
|
920 |
@type minor: int
|
921 |
@param minor: the device to detach from the local device
|
922 |
|
923 |
"""
|
924 |
cmd = self._cmd_gen.GenDetachCmd(minor)
|
925 |
result = utils.RunCmd(cmd) |
926 |
if result.failed:
|
927 |
base.ThrowError("drbd%d: can't detach local disk: %s",
|
928 |
minor, result.output) |
929 |
|
930 |
def _ShutdownNet(self, minor): |
931 |
"""Disconnect from the remote peer.
|
932 |
|
933 |
This fails if we don't have a local device.
|
934 |
|
935 |
@type minor: boolean
|
936 |
@param minor: the device to disconnect from the remote peer
|
937 |
|
938 |
"""
|
939 |
family = self._GetNetFamily(minor, self._lhost, self._rhost) |
940 |
cmd = self._cmd_gen.GenDisconnectCmd(minor, family,
|
941 |
self._lhost, self._lport, |
942 |
self._rhost, self._rport) |
943 |
result = utils.RunCmd(cmd) |
944 |
if result.failed:
|
945 |
base.ThrowError("drbd%d: can't shutdown network: %s",
|
946 |
minor, result.output) |
947 |
|
948 |
def Shutdown(self): |
949 |
"""Shutdown the DRBD device.
|
950 |
|
951 |
"""
|
952 |
if self.minor is None and not self.Attach(): |
953 |
logging.info("drbd%d: not attached during Shutdown()", self._aminor) |
954 |
return
|
955 |
|
956 |
try:
|
957 |
DRBD8.ShutdownAll(self.minor)
|
958 |
finally:
|
959 |
self.minor = None |
960 |
self.dev_path = None |
961 |
|
962 |
def Remove(self): |
963 |
"""Stub remove for DRBD devices.
|
964 |
|
965 |
"""
|
966 |
self.Shutdown()
|
967 |
|
968 |
def Rename(self, new_id): |
969 |
"""Rename a device.
|
970 |
|
971 |
This is not supported for drbd devices.
|
972 |
|
973 |
"""
|
974 |
raise errors.ProgrammerError("Can't rename a drbd device") |
975 |
|
976 |
def Grow(self, amount, dryrun, backingstore, excl_stor): |
977 |
"""Resize the DRBD device and its backing storage.
|
978 |
|
979 |
See L{BlockDev.Grow} for parameter description.
|
980 |
|
981 |
"""
|
982 |
if self.minor is None: |
983 |
base.ThrowError("drbd%d: Grow called while not attached", self._aminor) |
984 |
if len(self._children) != 2 or None in self._children: |
985 |
base.ThrowError("drbd%d: cannot grow diskless device", self.minor) |
986 |
self._children[0].Grow(amount, dryrun, backingstore, excl_stor) |
987 |
if dryrun or backingstore: |
988 |
# DRBD does not support dry-run mode and is not backing storage,
|
989 |
# so we'll return here
|
990 |
return
|
991 |
cmd = self._cmd_gen.GenResizeCmd(self.minor, self.size + amount) |
992 |
result = utils.RunCmd(cmd) |
993 |
if result.failed:
|
994 |
base.ThrowError("drbd%d: resize failed: %s", self.minor, result.output) |
995 |
|
996 |
@classmethod
|
997 |
def _InitMeta(cls, minor, dev_path): |
998 |
"""Initialize a meta device.
|
999 |
|
1000 |
This will not work if the given minor is in use.
|
1001 |
|
1002 |
@type minor: int
|
1003 |
@param minor: the DRBD minor whose (future) meta device should be
|
1004 |
initialized
|
1005 |
@type dev_path: string
|
1006 |
@param dev_path: path to the meta device to initialize
|
1007 |
|
1008 |
"""
|
1009 |
# Zero the metadata first, in order to make sure drbdmeta doesn't
|
1010 |
# try to auto-detect existing filesystems or similar (see
|
1011 |
# http://code.google.com/p/ganeti/issues/detail?id=182); we only
|
1012 |
# care about the first 128MB of data in the device, even though it
|
1013 |
# can be bigger
|
1014 |
result = utils.RunCmd([constants.DD_CMD, |
1015 |
"if=/dev/zero", "of=%s" % dev_path, |
1016 |
"bs=1048576", "count=128", "oflag=direct"]) |
1017 |
if result.failed:
|
1018 |
base.ThrowError("Can't wipe the meta device: %s", result.output)
|
1019 |
|
1020 |
info = DRBD8.GetProcInfo() |
1021 |
cmd_gen = DRBD8.GetCmdGenerator(info) |
1022 |
cmd = cmd_gen.GenInitMetaCmd(minor, dev_path) |
1023 |
|
1024 |
result = utils.RunCmd(cmd) |
1025 |
if result.failed:
|
1026 |
base.ThrowError("Can't initialize meta device: %s", result.output)
|
1027 |
|
1028 |
@classmethod
|
1029 |
def Create(cls, unique_id, children, size, spindles, params, excl_stor, |
1030 |
dyn_params, *_): |
1031 |
"""Create a new DRBD8 device.
|
1032 |
|
1033 |
Since DRBD devices are not created per se, just assembled, this
|
1034 |
function only initializes the metadata.
|
1035 |
|
1036 |
"""
|
1037 |
if len(children) != 2: |
1038 |
raise errors.ProgrammerError("Invalid setup for the drbd device") |
1039 |
if excl_stor:
|
1040 |
raise errors.ProgrammerError("DRBD device requested with" |
1041 |
" exclusive_storage")
|
1042 |
if constants.DDP_LOCAL_MINOR not in dyn_params: |
1043 |
raise errors.ProgrammerError("Invalid dynamic params for drbd device %s" |
1044 |
% dyn_params) |
1045 |
# check that the minor is unused
|
1046 |
aminor = dyn_params[constants.DDP_LOCAL_MINOR] |
1047 |
|
1048 |
info = DRBD8.GetProcInfo() |
1049 |
if info.HasMinorStatus(aminor):
|
1050 |
status = info.GetMinorStatus(aminor) |
1051 |
in_use = status.is_in_use |
1052 |
else:
|
1053 |
in_use = False
|
1054 |
if in_use:
|
1055 |
base.ThrowError("drbd%d: minor is already in use at Create() time",
|
1056 |
aminor) |
1057 |
meta = children[1]
|
1058 |
meta.Assemble() |
1059 |
if not meta.Attach(): |
1060 |
base.ThrowError("drbd%d: can't attach to meta device '%s'",
|
1061 |
aminor, meta) |
1062 |
cls._CheckMetaSize(meta.dev_path) |
1063 |
cls._InitMeta(aminor, meta.dev_path) |
1064 |
return cls(unique_id, children, size, params, dyn_params)
|
1065 |
|
1066 |
|
1067 |
def _CanReadDevice(path): |
1068 |
"""Check if we can read from the given device.
|
1069 |
|
1070 |
This tries to read the first 128k of the device.
|
1071 |
|
1072 |
@type path: string
|
1073 |
|
1074 |
"""
|
1075 |
try:
|
1076 |
utils.ReadFile(path, size=_DEVICE_READ_SIZE) |
1077 |
return True |
1078 |
except EnvironmentError: |
1079 |
logging.warning("Can't read from device %s", path, exc_info=True) |
1080 |
return False |