4 # Copyright (C) 2006, 2007 Google Inc.
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful, but
12 # WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 # General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program; if not, write to the Free Software
18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 """Block device abstraction"""
27 import pyparsing as pyp
31 from ganeti import utils
32 from ganeti import errors
33 from ganeti import constants
36 def _IgnoreError(fn, *args, **kwargs):
37 """Executes the given function, ignoring BlockDeviceErrors.
39 This is used in order to simplify the execution of cleanup or
43 @return: True when fn didn't raise an exception, False otherwise
49 except errors.BlockDeviceError, err:
50 logging.warning("Caught BlockDeviceError but ignoring: %s" % str(err))
54 def _ThrowError(msg, *args):
55 """Log an error to the node daemon and the raise an exception.
58 @param msg: the text of the exception
59 @raise errors.BlockDeviceError
65 raise errors.BlockDeviceError(msg)
68 class BlockDev(object):
69 """Block device abstract class.
71 A block device can be in the following states:
72 - not existing on the system, and by `Create()` it goes into:
73 - existing but not setup/not active, and by `Assemble()` goes into:
74 - active read-write and by `Open()` it goes into
75 - online (=used, or ready for use)
77 A device can also be online but read-only, however we are not using
78 the readonly state (LV has it, if needed in the future) and we are
79 usually looking at this like at a stack, so it's easier to
80 conceptualise the transition from not-existing to online and back
83 The many different states of the device are due to the fact that we
84 need to cover many device types:
85 - logical volumes are created, lvchange -a y $lv, and used
86 - drbd devices are attached to a local disk/remote peer and made primary
88 A block device is identified by three items:
89 - the /dev path of the device (dynamic)
90 - a unique ID of the device (static)
91 - it's major/minor pair (dynamic)
93 Not all devices implement both the first two as distinct items. LVM
94 logical volumes have their unique ID (the pair volume group, logical
95 volume name) in a 1-to-1 relation to the dev path. For DRBD devices,
96 the /dev path is again dynamic and the unique id is the pair (host1,
99 You can get to a device in two ways:
100 - creating the (real) device, which returns you
101 an attached instance (lvcreate)
102 - attaching of a python instance to an existing (real) device
104 The second point, the attachement to a device, is different
105 depending on whether the device is assembled or not. At init() time,
106 we search for a device with the same unique_id as us. If found,
107 good. It also means that the device is already assembled. If not,
108 after assembly we'll have our correct major/minor.
111 def __init__(self, unique_id, children):
112 self._children = children
114 self.unique_id = unique_id
117 self.attached = False
120 """Assemble the device from its components.
122 Implementations of this method by child classes must ensure that:
123 - after the device has been assembled, it knows its major/minor
124 numbers; this allows other devices (usually parents) to probe
125 correctly for their children
126 - calling this method on an existing, in-use device is safe
127 - if the device is already configured (and in an OK state),
128 this method is idempotent
134 """Find a device which matches our config and attach to it.
137 raise NotImplementedError
140 """Notifies that the device will no longer be used for I/O.
143 raise NotImplementedError
146 def Create(cls, unique_id, children, size):
147 """Create the device.
149 If the device cannot be created, it will return None
150 instead. Error messages go to the logging system.
152 Note that for some devices, the unique_id is used, and for other,
153 the children. The idea is that these two, taken together, are
154 enough for both creation and assembly (later).
157 raise NotImplementedError
160 """Remove this device.
162 This makes sense only for some of the device types: LV and file
163 storeage. Also note that if the device can't attach, the removal
167 raise NotImplementedError
169 def Rename(self, new_id):
170 """Rename this device.
172 This may or may not make sense for a given device type.
175 raise NotImplementedError
177 def Open(self, force=False):
178 """Make the device ready for use.
180 This makes the device ready for I/O. For now, just the DRBD
183 The force parameter signifies that if the device has any kind of
184 --force thing, it should be used, we know what we are doing.
187 raise NotImplementedError
190 """Shut down the device, freeing its children.
192 This undoes the `Assemble()` work, except for the child
193 assembling; as such, the children on the device are still
194 assembled after this call.
197 raise NotImplementedError
199 def SetSyncSpeed(self, speed):
200 """Adjust the sync speed of the mirror.
202 In case this is not a mirroring device, this is no-op.
207 for child in self._children:
208 result = result and child.SetSyncSpeed(speed)
211 def GetSyncStatus(self):
212 """Returns the sync status of the device.
214 If this device is a mirroring device, this function returns the
215 status of the mirror.
217 If sync_percent is None, it means the device is not syncing.
219 If estimated_time is None, it means we can't estimate
220 the time needed, otherwise it's the time left in seconds.
222 If is_degraded is True, it means the device is missing
223 redundancy. This is usually a sign that something went wrong in
224 the device setup, if sync_percent is None.
226 The ldisk parameter represents the degradation of the local
227 data. This is only valid for some devices, the rest will always
228 return False (not degraded).
231 @return: (sync_percent, estimated_time, is_degraded, ldisk)
234 return None, None, False, False
237 def CombinedSyncStatus(self):
238 """Calculate the mirror status recursively for our children.
240 The return value is the same as for `GetSyncStatus()` except the
241 minimum percent and maximum time are calculated across our
245 min_percent, max_time, is_degraded, ldisk = self.GetSyncStatus()
247 for child in self._children:
248 c_percent, c_time, c_degraded, c_ldisk = child.GetSyncStatus()
249 if min_percent is None:
250 min_percent = c_percent
251 elif c_percent is not None:
252 min_percent = min(min_percent, c_percent)
255 elif c_time is not None:
256 max_time = max(max_time, c_time)
257 is_degraded = is_degraded or c_degraded
258 ldisk = ldisk or c_ldisk
259 return min_percent, max_time, is_degraded, ldisk
262 def SetInfo(self, text):
263 """Update metadata with info text.
265 Only supported for some device types.
268 for child in self._children:
271 def Grow(self, amount):
272 """Grow the block device.
274 @param amount: the amount (in mebibytes) to grow with
277 raise NotImplementedError
280 return ("<%s: unique_id: %s, children: %s, %s:%s, %s>" %
281 (self.__class__, self.unique_id, self._children,
282 self.major, self.minor, self.dev_path))
285 class LogicalVolume(BlockDev):
286 """Logical Volume block device.
289 def __init__(self, unique_id, children):
290 """Attaches to a LV device.
292 The unique_id is a tuple (vg_name, lv_name)
295 super(LogicalVolume, self).__init__(unique_id, children)
296 if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
297 raise ValueError("Invalid configuration data %s" % str(unique_id))
298 self._vg_name, self._lv_name = unique_id
299 self.dev_path = "/dev/%s/%s" % (self._vg_name, self._lv_name)
300 self._degraded = True
301 self.major = self.minor = None
305 def Create(cls, unique_id, children, size):
306 """Create a new logical volume.
309 if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
310 raise errors.ProgrammerError("Invalid configuration data %s" %
312 vg_name, lv_name = unique_id
313 pvs_info = cls.GetPVInfo(vg_name)
315 _ThrowError("Can't compute PV info for vg %s", vg_name)
319 pvlist = [ pv[1] for pv in pvs_info ]
320 free_size = sum([ pv[0] for pv in pvs_info ])
322 # The size constraint should have been checked from the master before
323 # calling the create function.
325 _ThrowError("Not enough free space: required %s,"
326 " available %s", size, free_size)
327 result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-n%s" % lv_name,
330 _ThrowError("LV create failed (%s): %s",
331 result.fail_reason, result.output)
332 return LogicalVolume(unique_id, children)
335 def GetPVInfo(vg_name):
336 """Get the free space info for PVs in a volume group.
338 @param vg_name: the volume group name
341 @return: list of tuples (free_space, name) with free_space in mebibytes
344 command = ["pvs", "--noheadings", "--nosuffix", "--units=m",
345 "-opv_name,vg_name,pv_free,pv_attr", "--unbuffered",
347 result = utils.RunCmd(command)
349 logging.error("Can't get the PV information: %s - %s",
350 result.fail_reason, result.output)
353 for line in result.stdout.splitlines():
354 fields = line.strip().split(':')
356 logging.error("Can't parse pvs output: line '%s'", line)
358 # skip over pvs from another vg or ones which are not allocatable
359 if fields[1] != vg_name or fields[3][0] != 'a':
361 data.append((float(fields[2]), fields[0]))
366 """Remove this logical volume.
369 if not self.minor and not self.Attach():
370 # the LV does not exist
372 result = utils.RunCmd(["lvremove", "-f", "%s/%s" %
373 (self._vg_name, self._lv_name)])
375 _ThrowError("Can't lvremove: %s - %s", result.fail_reason, result.output)
377 def Rename(self, new_id):
378 """Rename this logical volume.
381 if not isinstance(new_id, (tuple, list)) or len(new_id) != 2:
382 raise errors.ProgrammerError("Invalid new logical id '%s'" % new_id)
383 new_vg, new_name = new_id
384 if new_vg != self._vg_name:
385 raise errors.ProgrammerError("Can't move a logical volume across"
386 " volume groups (from %s to to %s)" %
387 (self._vg_name, new_vg))
388 result = utils.RunCmd(["lvrename", new_vg, self._lv_name, new_name])
390 _ThrowError("Failed to rename the logical volume: %s", result.output)
391 self._lv_name = new_name
392 self.dev_path = "/dev/%s/%s" % (self._vg_name, self._lv_name)
395 """Attach to an existing LV.
397 This method will try to see if an existing and active LV exists
398 which matches our name. If so, its major/minor will be
402 self.attached = False
403 result = utils.RunCmd(["lvs", "--noheadings", "--separator=,",
404 "-olv_attr,lv_kernel_major,lv_kernel_minor",
407 logging.error("Can't find LV %s: %s, %s",
408 self.dev_path, result.fail_reason, result.output)
410 out = result.stdout.strip().rstrip(',')
413 logging.error("Can't parse LVS output, len(%s) != 3", str(out))
416 status, major, minor = out[:3]
418 logging.error("lvs lv_attr is not 6 characters (%s)", status)
424 except ValueError, err:
425 logging.error("lvs major/minor cannot be parsed: %s", str(err))
429 self._degraded = status[0] == 'v' # virtual volume, i.e. doesn't backing
435 """Assemble the device.
437 We alway run `lvchange -ay` on the LV to ensure it's active before
438 use, as there were cases when xenvg was not active after boot
439 (also possibly after disk issues).
442 result = utils.RunCmd(["lvchange", "-ay", self.dev_path])
444 _ThrowError("Can't activate lv %s: %s", self.dev_path, result.output)
447 """Shutdown the device.
449 This is a no-op for the LV device type, as we don't deactivate the
455 def GetSyncStatus(self):
456 """Returns the sync status of the device.
458 If this device is a mirroring device, this function returns the
459 status of the mirror.
461 For logical volumes, sync_percent and estimated_time are always
462 None (no recovery in progress, as we don't handle the mirrored LV
463 case). The is_degraded parameter is the inverse of the ldisk
466 For the ldisk parameter, we check if the logical volume has the
467 'virtual' type, which means it's not backed by existing storage
468 anymore (read from it return I/O error). This happens after a
469 physical disk failure and subsequent 'vgreduce --removemissing' on
472 The status was already read in Attach, so we just return it.
475 @return: (sync_percent, estimated_time, is_degraded, ldisk)
478 return None, None, self._degraded, self._degraded
480 def Open(self, force=False):
481 """Make the device ready for I/O.
483 This is a no-op for the LV device type.
489 """Notifies that the device will no longer be used for I/O.
491 This is a no-op for the LV device type.
496 def Snapshot(self, size):
497 """Create a snapshot copy of an lvm block device.
500 snap_name = self._lv_name + ".snap"
502 # remove existing snapshot if found
503 snap = LogicalVolume((self._vg_name, snap_name), None)
504 _IgnoreError(snap.Remove)
506 pvs_info = self.GetPVInfo(self._vg_name)
508 _ThrowError("Can't compute PV info for vg %s", self._vg_name)
511 free_size, pv_name = pvs_info[0]
513 _ThrowError("Not enough free space: required %s,"
514 " available %s", size, free_size)
516 result = utils.RunCmd(["lvcreate", "-L%dm" % size, "-s",
517 "-n%s" % snap_name, self.dev_path])
519 _ThrowError("command: %s error: %s - %s",
520 result.cmd, result.fail_reason, result.output)
524 def SetInfo(self, text):
525 """Update metadata with info text.
528 BlockDev.SetInfo(self, text)
530 # Replace invalid characters
531 text = re.sub('^[^A-Za-z0-9_+.]', '_', text)
532 text = re.sub('[^-A-Za-z0-9_+.]', '_', text)
534 # Only up to 128 characters are allowed
537 result = utils.RunCmd(["lvchange", "--addtag", text,
540 _ThrowError("Command: %s error: %s - %s", result.cmd, result.fail_reason,
543 def Grow(self, amount):
544 """Grow the logical volume.
547 # we try multiple algorithms since the 'best' ones might not have
548 # space available in the right place, but later ones might (since
549 # they have less constraints); also note that only recent LVM
551 for alloc_policy in "contiguous", "cling", "normal":
552 result = utils.RunCmd(["lvextend", "--alloc", alloc_policy,
553 "-L", "+%dm" % amount, self.dev_path])
554 if not result.failed:
556 _ThrowError("Can't grow LV %s: %s", self.dev_path, result.output)
559 class DRBD8Status(object):
560 """A DRBD status representation class.
562 Note that this doesn't support unconfigured devices (cs:Unconfigured).
565 UNCONF_RE = re.compile(r"\s*[0-9]+:\s*cs:Unconfigured$")
566 LINE_RE = re.compile(r"\s*[0-9]+:\s*cs:(\S+)\s+st:([^/]+)/(\S+)"
567 "\s+ds:([^/]+)/(\S+)\s+.*$")
568 SYNC_RE = re.compile(r"^.*\ssync'ed:\s*([0-9.]+)%.*"
569 "\sfinish: ([0-9]+):([0-9]+):([0-9]+)\s.*$")
571 def __init__(self, procline):
572 u = self.UNCONF_RE.match(procline)
574 self.cstatus = "Unconfigured"
575 self.lrole = self.rrole = self.ldisk = self.rdisk = None
577 m = self.LINE_RE.match(procline)
579 raise errors.BlockDeviceError("Can't parse input data '%s'" % procline)
580 self.cstatus = m.group(1)
581 self.lrole = m.group(2)
582 self.rrole = m.group(3)
583 self.ldisk = m.group(4)
584 self.rdisk = m.group(5)
586 # end reading of data from the LINE_RE or UNCONF_RE
588 self.is_standalone = self.cstatus == "StandAlone"
589 self.is_wfconn = self.cstatus == "WFConnection"
590 self.is_connected = self.cstatus == "Connected"
591 self.is_primary = self.lrole == "Primary"
592 self.is_secondary = self.lrole == "Secondary"
593 self.peer_primary = self.rrole == "Primary"
594 self.peer_secondary = self.rrole == "Secondary"
595 self.both_primary = self.is_primary and self.peer_primary
596 self.both_secondary = self.is_secondary and self.peer_secondary
598 self.is_diskless = self.ldisk == "Diskless"
599 self.is_disk_uptodate = self.ldisk == "UpToDate"
601 self.is_in_resync = self.cstatus in ("SyncSource", "SyncTarget")
602 self.is_in_use = self.cstatus != "Unconfigured"
604 m = self.SYNC_RE.match(procline)
606 self.sync_percent = float(m.group(1))
607 hours = int(m.group(2))
608 minutes = int(m.group(3))
609 seconds = int(m.group(4))
610 self.est_time = hours * 3600 + minutes * 60 + seconds
612 self.sync_percent = None
615 self.is_sync_target = self.peer_sync_source = self.cstatus == "SyncTarget"
616 self.peer_sync_target = self.is_sync_source = self.cstatus == "SyncSource"
617 self.is_resync = self.is_sync_target or self.is_sync_source
620 class BaseDRBD(BlockDev):
623 This class contains a few bits of common functionality between the
624 0.7 and 8.x versions of DRBD.
627 _VERSION_RE = re.compile(r"^version: (\d+)\.(\d+)\.(\d+)"
628 r" \(api:(\d+)/proto:(\d+)(?:-(\d+))?\)")
631 _ST_UNCONFIGURED = "Unconfigured"
632 _ST_WFCONNECTION = "WFConnection"
633 _ST_CONNECTED = "Connected"
635 _STATUS_FILE = "/proc/drbd"
638 def _GetProcData(filename=_STATUS_FILE):
639 """Return data from /proc/drbd.
643 stat = open(filename, "r")
645 data = stat.read().splitlines()
648 except EnvironmentError, err:
649 if err.errno == errno.ENOENT:
650 _ThrowError("The file %s cannot be opened, check if the module"
651 " is loaded (%s)", filename, str(err))
653 _ThrowError("Can't read the DRBD proc file %s: %s", filename, str(err))
655 _ThrowError("Can't read any data from %s", filename)
659 def _MassageProcData(data):
660 """Transform the output of _GetProdData into a nicer form.
662 @return: a dictionary of minor: joined lines from /proc/drbd
666 lmatch = re.compile("^ *([0-9]+):.*$")
668 old_minor = old_line = None
670 lresult = lmatch.match(line)
671 if lresult is not None:
672 if old_minor is not None:
673 results[old_minor] = old_line
674 old_minor = int(lresult.group(1))
677 if old_minor is not None:
678 old_line += " " + line.strip()
680 if old_minor is not None:
681 results[old_minor] = old_line
685 def _GetVersion(cls):
686 """Return the DRBD version.
688 This will return a dict with keys:
694 - proto2 (only on drbd > 8.2.X)
697 proc_data = cls._GetProcData()
698 first_line = proc_data[0].strip()
699 version = cls._VERSION_RE.match(first_line)
701 raise errors.BlockDeviceError("Can't parse DRBD version from '%s'" %
704 values = version.groups()
705 retval = {'k_major': int(values[0]),
706 'k_minor': int(values[1]),
707 'k_point': int(values[2]),
708 'api': int(values[3]),
709 'proto': int(values[4]),
711 if values[5] is not None:
712 retval['proto2'] = values[5]
718 """Return the path to a drbd device for a given minor.
721 return "/dev/drbd%d" % minor
724 def GetUsedDevs(cls):
725 """Compute the list of used DRBD devices.
728 data = cls._GetProcData()
731 valid_line = re.compile("^ *([0-9]+): cs:([^ ]+).*$")
733 match = valid_line.match(line)
736 minor = int(match.group(1))
737 state = match.group(2)
738 if state == cls._ST_UNCONFIGURED:
740 used_devs[minor] = state, line
744 def _SetFromMinor(self, minor):
745 """Set our parameters based on the given minor.
747 This sets our minor variable and our dev_path.
751 self.minor = self.dev_path = None
752 self.attached = False
755 self.dev_path = self._DevPath(minor)
759 def _CheckMetaSize(meta_device):
760 """Check if the given meta device looks like a valid one.
762 This currently only check the size, which must be around
766 result = utils.RunCmd(["blockdev", "--getsize", meta_device])
768 _ThrowError("Failed to get device size: %s - %s",
769 result.fail_reason, result.output)
771 sectors = int(result.stdout)
773 _ThrowError("Invalid output from blockdev: '%s'", result.stdout)
774 bytes = sectors * 512
775 if bytes < 128 * 1024 * 1024: # less than 128MiB
776 _ThrowError("Meta device too small (%.2fMib)", (bytes / 1024 / 1024))
777 if bytes > (128 + 32) * 1024 * 1024: # account for an extra (big) PE on LVM
778 _ThrowError("Meta device too big (%.2fMiB)", (bytes / 1024 / 1024))
780 def Rename(self, new_id):
783 This is not supported for drbd devices.
786 raise errors.ProgrammerError("Can't rename a drbd device")
789 class DRBD8(BaseDRBD):
790 """DRBD v8.x block device.
792 This implements the local host part of the DRBD device, i.e. it
793 doesn't do anything to the supposed peer. If you need a fully
794 connected DRBD pair, you need to use this class on both hosts.
796 The unique_id for the drbd device is the (local_ip, local_port,
797 remote_ip, remote_port) tuple, and it must have two children: the
798 data device and the meta_device. The meta device is checked for
799 valid size and is zeroed on create.
806 _NET_RECONFIG_TIMEOUT = 60
808 def __init__(self, unique_id, children):
809 if children and children.count(None) > 0:
811 super(DRBD8, self).__init__(unique_id, children)
812 self.major = self._DRBD_MAJOR
813 version = self._GetVersion()
814 if version['k_major'] != 8 :
815 _ThrowError("Mismatch in DRBD kernel version and requested ganeti"
816 " usage: kernel is %s.%s, ganeti wants 8.x",
817 version['k_major'], version['k_minor'])
819 if len(children) not in (0, 2):
820 raise ValueError("Invalid configuration data %s" % str(children))
821 if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 6:
822 raise ValueError("Invalid configuration data %s" % str(unique_id))
823 (self._lhost, self._lport,
824 self._rhost, self._rport,
825 self._aminor, self._secret) = unique_id
826 if (self._lhost is not None and self._lhost == self._rhost and
827 self._lport == self._rport):
828 raise ValueError("Invalid configuration data, same local/remote %s" %
833 def _InitMeta(cls, minor, dev_path):
834 """Initialize a meta device.
836 This will not work if the given minor is in use.
839 result = utils.RunCmd(["drbdmeta", "--force", cls._DevPath(minor),
840 "v08", dev_path, "0", "create-md"])
842 _ThrowError("Can't initialize meta device: %s", result.output)
845 def _FindUnusedMinor(cls):
846 """Find an unused DRBD device.
848 This is specific to 8.x as the minors are allocated dynamically,
849 so non-existing numbers up to a max minor count are actually free.
852 data = cls._GetProcData()
854 unused_line = re.compile("^ *([0-9]+): cs:Unconfigured$")
855 used_line = re.compile("^ *([0-9]+): cs:")
858 match = unused_line.match(line)
860 return int(match.group(1))
861 match = used_line.match(line)
863 minor = int(match.group(1))
864 highest = max(highest, minor)
865 if highest is None: # there are no minors in use at all
867 if highest >= cls._MAX_MINORS:
868 logging.error("Error: no free drbd minors!")
869 raise errors.BlockDeviceError("Can't find a free DRBD minor")
873 def _GetShowParser(cls):
874 """Return a parser for `drbd show` output.
876 This will either create or return an already-create parser for the
877 output of the command `drbd show`.
880 if cls._PARSE_SHOW is not None:
881 return cls._PARSE_SHOW
884 lbrace = pyp.Literal("{").suppress()
885 rbrace = pyp.Literal("}").suppress()
886 semi = pyp.Literal(";").suppress()
887 # this also converts the value to an int
888 number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t: int(t[0]))
890 comment = pyp.Literal ("#") + pyp.Optional(pyp.restOfLine)
891 defa = pyp.Literal("_is_default").suppress()
892 dbl_quote = pyp.Literal('"').suppress()
894 keyword = pyp.Word(pyp.alphanums + '-')
897 value = pyp.Word(pyp.alphanums + '_-/.:')
898 quoted = dbl_quote + pyp.CharsNotIn('"') + dbl_quote
899 addr_port = (pyp.Word(pyp.nums + '.') + pyp.Literal(':').suppress() +
901 # meta device, extended syntax
902 meta_value = ((value ^ quoted) + pyp.Literal('[').suppress() +
903 number + pyp.Word(']').suppress())
906 stmt = (~rbrace + keyword + ~lbrace +
907 pyp.Optional(addr_port ^ value ^ quoted ^ meta_value) +
908 pyp.Optional(defa) + semi +
909 pyp.Optional(pyp.restOfLine).suppress())
912 section_name = pyp.Word(pyp.alphas + '_')
913 section = section_name + lbrace + pyp.ZeroOrMore(pyp.Group(stmt)) + rbrace
915 bnf = pyp.ZeroOrMore(pyp.Group(section ^ stmt))
918 cls._PARSE_SHOW = bnf
923 def _GetShowData(cls, minor):
924 """Return the `drbdsetup show` data for a minor.
927 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
929 logging.error("Can't display the drbd config: %s - %s",
930 result.fail_reason, result.output)
935 def _GetDevInfo(cls, out):
936 """Parse details about a given DRBD minor.
938 This return, if available, the local backing device (as a path)
939 and the local and remote (ip, port) information from a string
940 containing the output of the `drbdsetup show` command as returned
948 bnf = cls._GetShowParser()
952 results = bnf.parseString(out)
953 except pyp.ParseException, err:
954 _ThrowError("Can't parse drbdsetup show output: %s", str(err))
956 # and massage the results into our desired format
957 for section in results:
959 if sname == "_this_host":
960 for lst in section[1:]:
962 data["local_dev"] = lst[1]
963 elif lst[0] == "meta-disk":
964 data["meta_dev"] = lst[1]
965 data["meta_index"] = lst[2]
966 elif lst[0] == "address":
967 data["local_addr"] = tuple(lst[1:])
968 elif sname == "_remote_host":
969 for lst in section[1:]:
970 if lst[0] == "address":
971 data["remote_addr"] = tuple(lst[1:])
974 def _MatchesLocal(self, info):
975 """Test if our local config matches with an existing device.
977 The parameter should be as returned from `_GetDevInfo()`. This
978 method tests if our local backing device is the same as the one in
979 the info parameter, in effect testing if we look like the given
984 backend, meta = self._children
986 backend = meta = None
988 if backend is not None:
989 retval = ("local_dev" in info and info["local_dev"] == backend.dev_path)
991 retval = ("local_dev" not in info)
994 retval = retval and ("meta_dev" in info and
995 info["meta_dev"] == meta.dev_path)
996 retval = retval and ("meta_index" in info and
997 info["meta_index"] == 0)
999 retval = retval and ("meta_dev" not in info and
1000 "meta_index" not in info)
1003 def _MatchesNet(self, info):
1004 """Test if our network config matches with an existing device.
1006 The parameter should be as returned from `_GetDevInfo()`. This
1007 method tests if our network configuration is the same as the one
1008 in the info parameter, in effect testing if we look like the given
1012 if (((self._lhost is None and not ("local_addr" in info)) and
1013 (self._rhost is None and not ("remote_addr" in info)))):
1016 if self._lhost is None:
1019 if not ("local_addr" in info and
1020 "remote_addr" in info):
1023 retval = (info["local_addr"] == (self._lhost, self._lport))
1024 retval = (retval and
1025 info["remote_addr"] == (self._rhost, self._rport))
1029 def _AssembleLocal(cls, minor, backend, meta):
1030 """Configure the local part of a DRBD device.
1033 args = ["drbdsetup", cls._DevPath(minor), "disk",
1034 backend, meta, "0", "-e", "detach", "--create-device"]
1035 result = utils.RunCmd(args)
1037 _ThrowError("drbd%d: can't attach local disk: %s", minor, result.output)
1040 def _AssembleNet(cls, minor, net_info, protocol,
1041 dual_pri=False, hmac=None, secret=None):
1042 """Configure the network part of the device.
1045 lhost, lport, rhost, rport = net_info
1046 if None in net_info:
1047 # we don't want network connection and actually want to make
1049 cls._ShutdownNet(minor)
1052 # Workaround for a race condition. When DRBD is doing its dance to
1053 # establish a connection with its peer, it also sends the
1054 # synchronization speed over the wire. In some cases setting the
1055 # sync speed only after setting up both sides can race with DRBD
1056 # connecting, hence we set it here before telling DRBD anything
1058 cls._SetMinorSyncSpeed(minor, constants.SYNC_SPEED)
1060 args = ["drbdsetup", cls._DevPath(minor), "net",
1061 "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport), protocol,
1062 "-A", "discard-zero-changes",
1069 args.extend(["-a", hmac, "-x", secret])
1070 result = utils.RunCmd(args)
1072 _ThrowError("drbd%d: can't setup network: %s - %s",
1073 minor, result.fail_reason, result.output)
1075 timeout = time.time() + 10
1077 while time.time() < timeout:
1078 info = cls._GetDevInfo(cls._GetShowData(minor))
1079 if not "local_addr" in info or not "remote_addr" in info:
1082 if (info["local_addr"] != (lhost, lport) or
1083 info["remote_addr"] != (rhost, rport)):
1089 _ThrowError("drbd%d: timeout while configuring network", minor)
1091 def AddChildren(self, devices):
1092 """Add a disk to the DRBD device.
1095 if self.minor is None:
1096 _ThrowError("drbd%d: can't attach to dbrd8 during AddChildren",
1098 if len(devices) != 2:
1099 _ThrowError("drbd%d: need two devices for AddChildren", self.minor)
1100 info = self._GetDevInfo(self._GetShowData(self.minor))
1101 if "local_dev" in info:
1102 _ThrowError("drbd%d: already attached to a local disk", self.minor)
1103 backend, meta = devices
1104 if backend.dev_path is None or meta.dev_path is None:
1105 _ThrowError("drbd%d: children not ready during AddChildren", self.minor)
1108 self._CheckMetaSize(meta.dev_path)
1109 self._InitMeta(self._FindUnusedMinor(), meta.dev_path)
1111 self._AssembleLocal(self.minor, backend.dev_path, meta.dev_path)
1112 self._children = devices
1114 def RemoveChildren(self, devices):
1115 """Detach the drbd device from local storage.
1118 if self.minor is None:
1119 _ThrowError("drbd%d: can't attach to drbd8 during RemoveChildren",
1121 # early return if we don't actually have backing storage
1122 info = self._GetDevInfo(self._GetShowData(self.minor))
1123 if "local_dev" not in info:
1125 if len(self._children) != 2:
1126 _ThrowError("drbd%d: we don't have two children: %s", self.minor,
1128 if self._children.count(None) == 2: # we don't actually have children :)
1129 logging.warning("drbd%d: requested detach while detached", self.minor)
1131 if len(devices) != 2:
1132 _ThrowError("drbd%d: we need two children in RemoveChildren", self.minor)
1133 for child, dev in zip(self._children, devices):
1134 if dev != child.dev_path:
1135 _ThrowError("drbd%d: mismatch in local storage (%s != %s) in"
1136 " RemoveChildren", self.minor, dev, child.dev_path)
1138 self._ShutdownLocal(self.minor)
1142 def _SetMinorSyncSpeed(cls, minor, kbytes):
1143 """Set the speed of the DRBD syncer.
1145 This is the low-level implementation.
1148 @param minor: the drbd minor whose settings we change
1150 @param kbytes: the speed in kbytes/second
1152 @return: the success of the operation
1155 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "syncer",
1156 "-r", "%d" % kbytes, "--create-device"])
1158 logging.error("Can't change syncer rate: %s - %s",
1159 result.fail_reason, result.output)
1160 return not result.failed
1162 def SetSyncSpeed(self, kbytes):
1163 """Set the speed of the DRBD syncer.
1166 @param kbytes: the speed in kbytes/second
1168 @return: the success of the operation
1171 if self.minor is None:
1172 logging.info("Not attached during SetSyncSpeed")
1174 children_result = super(DRBD8, self).SetSyncSpeed(kbytes)
1175 return self._SetMinorSyncSpeed(self.minor, kbytes) and children_result
1177 def GetProcStatus(self):
1178 """Return device data from /proc.
1181 if self.minor is None:
1182 _ThrowError("drbd%d: GetStats() called while not attached", self._aminor)
1183 proc_info = self._MassageProcData(self._GetProcData())
1184 if self.minor not in proc_info:
1185 _ThrowError("drbd%d: can't find myself in /proc", self.minor)
1186 return DRBD8Status(proc_info[self.minor])
1188 def GetSyncStatus(self):
1189 """Returns the sync status of the device.
1192 If sync_percent is None, it means all is ok
1193 If estimated_time is None, it means we can't esimate
1194 the time needed, otherwise it's the time left in seconds.
1197 We set the is_degraded parameter to True on two conditions:
1198 network not connected or local disk missing.
1200 We compute the ldisk parameter based on wheter we have a local
1204 @return: (sync_percent, estimated_time, is_degraded, ldisk)
1207 if self.minor is None and not self.Attach():
1208 _ThrowError("drbd%d: can't Attach() in GetSyncStatus", self._aminor)
1209 stats = self.GetProcStatus()
1210 ldisk = not stats.is_disk_uptodate
1211 is_degraded = not stats.is_connected
1212 return stats.sync_percent, stats.est_time, is_degraded or ldisk, ldisk
1214 def Open(self, force=False):
1215 """Make the local state primary.
1217 If the 'force' parameter is given, the '-o' option is passed to
1218 drbdsetup. Since this is a potentially dangerous operation, the
1219 force flag should be only given after creation, when it actually
1223 if self.minor is None and not self.Attach():
1224 logging.error("DRBD cannot attach to a device during open")
1226 cmd = ["drbdsetup", self.dev_path, "primary"]
1229 result = utils.RunCmd(cmd)
1231 _ThrowError("drbd%d: can't make drbd device primary: %s", self.minor,
1235 """Make the local state secondary.
1237 This will, of course, fail if the device is in use.
1240 if self.minor is None and not self.Attach():
1241 _ThrowError("drbd%d: can't Attach() in Close()", self._aminor)
1242 result = utils.RunCmd(["drbdsetup", self.dev_path, "secondary"])
1244 _ThrowError("drbd%d: can't switch drbd device to secondary: %s",
1245 self.minor, result.output)
1247 def DisconnectNet(self):
1248 """Removes network configuration.
1250 This method shutdowns the network side of the device.
1252 The method will wait up to a hardcoded timeout for the device to
1253 go into standalone after the 'disconnect' command before
1254 re-configuring it, as sometimes it takes a while for the
1255 disconnect to actually propagate and thus we might issue a 'net'
1256 command while the device is still connected. If the device will
1257 still be attached to the network and we time out, we raise an
1261 if self.minor is None:
1262 _ThrowError("drbd%d: disk not attached in re-attach net", self._aminor)
1264 if None in (self._lhost, self._lport, self._rhost, self._rport):
1265 _ThrowError("drbd%d: DRBD disk missing network info in"
1266 " DisconnectNet()", self.minor)
1268 ever_disconnected = _IgnoreError(self._ShutdownNet, self.minor)
1269 timeout_limit = time.time() + self._NET_RECONFIG_TIMEOUT
1270 sleep_time = 0.100 # we start the retry time at 100 miliseconds
1271 while time.time() < timeout_limit:
1272 status = self.GetProcStatus()
1273 if status.is_standalone:
1275 # retry the disconnect, it seems possible that due to a
1276 # well-time disconnect on the peer, my disconnect command might
1277 # be ingored and forgotten
1278 ever_disconnected = _IgnoreError(self._ShutdownNet, self.minor) or \
1280 time.sleep(sleep_time)
1281 sleep_time = min(2, sleep_time * 1.5)
1283 if not status.is_standalone:
1284 if ever_disconnected:
1285 msg = ("drbd%d: device did not react to the"
1286 " 'disconnect' command in a timely manner")
1288 msg = "drbd%d: can't shutdown network, even after multiple retries"
1289 _ThrowError(msg, self.minor)
1291 reconfig_time = time.time() - timeout_limit + self._NET_RECONFIG_TIMEOUT
1292 if reconfig_time > 15: # hardcoded alert limit
1293 logging.info("drbd%d: DisconnectNet: detach took %.3f seconds",
1294 self.minor, reconfig_time)
1296 def AttachNet(self, multimaster):
1297 """Reconnects the network.
1299 This method connects the network side of the device with a
1300 specified multi-master flag. The device needs to be 'Standalone'
1301 but have valid network configuration data.
1304 - multimaster: init the network in dual-primary mode
1307 if self.minor is None:
1308 _ThrowError("drbd%d: device not attached in AttachNet", self._aminor)
1310 if None in (self._lhost, self._lport, self._rhost, self._rport):
1311 _ThrowError("drbd%d: missing network info in AttachNet()", self.minor)
1313 status = self.GetProcStatus()
1315 if not status.is_standalone:
1316 _ThrowError("drbd%d: device is not standalone in AttachNet", self.minor)
1318 self._AssembleNet(self.minor,
1319 (self._lhost, self._lport, self._rhost, self._rport),
1320 constants.DRBD_NET_PROTOCOL, dual_pri=multimaster,
1321 hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
1324 """Check if our minor is configured.
1326 This doesn't do any device configurations - it only checks if the
1327 minor is in a state different from Unconfigured.
1329 Note that this function will not change the state of the system in
1330 any way (except in case of side-effects caused by reading from
1334 used_devs = self.GetUsedDevs()
1335 if self._aminor in used_devs:
1336 minor = self._aminor
1340 self._SetFromMinor(minor)
1341 return minor is not None
1344 """Assemble the drbd.
1347 - if we have a configured device, we try to ensure that it matches
1349 - if not, we create it from zero
1352 super(DRBD8, self).Assemble()
1355 if self.minor is None:
1356 # local device completely unconfigured
1357 self._FastAssemble()
1359 # we have to recheck the local and network status and try to fix
1361 self._SlowAssemble()
1363 def _SlowAssemble(self):
1364 """Assembles the DRBD device from a (partially) configured device.
1366 In case of partially attached (local device matches but no network
1367 setup), we perform the network attach. If successful, we re-test
1368 the attach if can return success.
1371 net_data = (self._lhost, self._lport, self._rhost, self._rport)
1372 for minor in (self._aminor,):
1373 info = self._GetDevInfo(self._GetShowData(minor))
1374 match_l = self._MatchesLocal(info)
1375 match_r = self._MatchesNet(info)
1377 if match_l and match_r:
1378 # everything matches
1381 if match_l and not match_r and "local_addr" not in info:
1382 # disk matches, but not attached to network, attach and recheck
1383 self._AssembleNet(minor, net_data, constants.DRBD_NET_PROTOCOL,
1384 hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
1385 if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
1388 _ThrowError("drbd%d: network attach successful, but 'drbdsetup"
1389 " show' disagrees", minor)
1391 if match_r and "local_dev" not in info:
1392 # no local disk, but network attached and it matches
1393 self._AssembleLocal(minor, self._children[0].dev_path,
1394 self._children[1].dev_path)
1395 if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
1398 _ThrowError("drbd%d: disk attach successful, but 'drbdsetup"
1399 " show' disagrees", minor)
1401 # this case must be considered only if we actually have local
1402 # storage, i.e. not in diskless mode, because all diskless
1403 # devices are equal from the point of view of local
1405 if (match_l and "local_dev" in info and
1406 not match_r and "local_addr" in info):
1407 # strange case - the device network part points to somewhere
1408 # else, even though its local storage is ours; as we own the
1409 # drbd space, we try to disconnect from the remote peer and
1410 # reconnect to our correct one
1412 self._ShutdownNet(minor)
1413 except errors.BlockDeviceError, err:
1414 _ThrowError("drbd%d: device has correct local storage, wrong"
1415 " remote peer and is unable to disconnect in order"
1416 " to attach to the correct peer: %s", minor, str(err))
1417 # note: _AssembleNet also handles the case when we don't want
1418 # local storage (i.e. one or more of the _[lr](host|port) is
1420 self._AssembleNet(minor, net_data, constants.DRBD_NET_PROTOCOL,
1421 hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
1422 if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
1425 _ThrowError("drbd%d: network attach successful, but 'drbdsetup"
1426 " show' disagrees", minor)
1431 self._SetFromMinor(minor)
1433 _ThrowError("drbd%d: cannot activate, unknown or unhandled reason",
1436 def _FastAssemble(self):
1437 """Assemble the drbd device from zero.
1439 This is run when in Assemble we detect our minor is unused.
1442 minor = self._aminor
1443 if self._children and self._children[0] and self._children[1]:
1444 self._AssembleLocal(minor, self._children[0].dev_path,
1445 self._children[1].dev_path)
1446 if self._lhost and self._lport and self._rhost and self._rport:
1447 self._AssembleNet(minor,
1448 (self._lhost, self._lport, self._rhost, self._rport),
1449 constants.DRBD_NET_PROTOCOL,
1450 hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
1451 self._SetFromMinor(minor)
1454 def _ShutdownLocal(cls, minor):
1455 """Detach from the local device.
1457 I/Os will continue to be served from the remote device. If we
1458 don't have a remote device, this operation will fail.
1461 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "detach"])
1463 _ThrowError("drbd%d: can't detach local disk: %s", minor, result.output)
1466 def _ShutdownNet(cls, minor):
1467 """Disconnect from the remote peer.
1469 This fails if we don't have a local device.
1472 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disconnect"])
1474 _ThrowError("drbd%d: can't shutdown network: %s", minor, result.output)
1477 def _ShutdownAll(cls, minor):
1478 """Deactivate the device.
1480 This will, of course, fail if the device is in use.
1483 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "down"])
1485 _ThrowError("drbd%d: can't shutdown drbd device: %s",
1486 minor, result.output)
1489 """Shutdown the DRBD device.
1492 if self.minor is None and not self.Attach():
1493 logging.info("drbd%d: not attached during Shutdown()", self._aminor)
1497 self.dev_path = None
1498 self._ShutdownAll(minor)
1501 """Stub remove for DRBD devices.
1507 def Create(cls, unique_id, children, size):
1508 """Create a new DRBD8 device.
1510 Since DRBD devices are not created per se, just assembled, this
1511 function only initializes the metadata.
1514 if len(children) != 2:
1515 raise errors.ProgrammerError("Invalid setup for the drbd device")
1516 # check that the minor is unused
1517 aminor = unique_id[4]
1518 proc_info = cls._MassageProcData(cls._GetProcData())
1519 if aminor in proc_info:
1520 status = DRBD8Status(proc_info[aminor])
1521 in_use = status.is_in_use
1525 _ThrowError("drbd%d: minor is already in use at Create() time", aminor)
1528 if not meta.Attach():
1529 _ThrowError("drbd%d: can't attach to meta device '%s'",
1531 cls._CheckMetaSize(meta.dev_path)
1532 cls._InitMeta(aminor, meta.dev_path)
1533 return cls(unique_id, children)
1535 def Grow(self, amount):
1536 """Resize the DRBD device and its backing storage.
1539 if self.minor is None:
1540 _ThrowError("drbd%d: Grow called while not attached", self._aminor)
1541 if len(self._children) != 2 or None in self._children:
1542 _ThrowError("drbd%d: cannot grow diskless device", self.minor)
1543 self._children[0].Grow(amount)
1544 result = utils.RunCmd(["drbdsetup", self.dev_path, "resize"])
1546 _ThrowError("drbd%d: resize failed: %s", self.minor, result.output)
1549 class FileStorage(BlockDev):
1552 This class represents the a file storage backend device.
1554 The unique_id for the file device is a (file_driver, file_path) tuple.
1557 def __init__(self, unique_id, children):
1558 """Initalizes a file device backend.
1562 raise errors.BlockDeviceError("Invalid setup for file device")
1563 super(FileStorage, self).__init__(unique_id, children)
1564 if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
1565 raise ValueError("Invalid configuration data %s" % str(unique_id))
1566 self.driver = unique_id[0]
1567 self.dev_path = unique_id[1]
1571 """Assemble the device.
1573 Checks whether the file device exists, raises BlockDeviceError otherwise.
1576 if not os.path.exists(self.dev_path):
1577 _ThrowError("File device '%s' does not exist" % self.dev_path)
1580 """Shutdown the device.
1582 This is a no-op for the file type, as we don't deacivate
1583 the file on shutdown.
1588 def Open(self, force=False):
1589 """Make the device ready for I/O.
1591 This is a no-op for the file type.
1597 """Notifies that the device will no longer be used for I/O.
1599 This is a no-op for the file type.
1605 """Remove the file backing the block device.
1608 @return: True if the removal was successful
1612 os.remove(self.dev_path)
1613 except OSError, err:
1614 if err.errno != errno.ENOENT:
1615 _ThrowError("Can't remove file '%s': %s", self.dev_path, err)
1618 """Attach to an existing file.
1620 Check if this file already exists.
1623 @return: True if file exists
1626 self.attached = os.path.exists(self.dev_path)
1627 return self.attached
1630 def Create(cls, unique_id, children, size):
1631 """Create a new file.
1633 @param size: the size of file in MiB
1635 @rtype: L{bdev.FileStorage}
1636 @return: an instance of FileStorage
1639 if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
1640 raise ValueError("Invalid configuration data %s" % str(unique_id))
1641 dev_path = unique_id[1]
1642 if os.path.exists(dev_path):
1643 _ThrowError("File already existing: %s", dev_path)
1645 f = open(dev_path, 'w')
1646 f.truncate(size * 1024 * 1024)
1648 except IOError, err:
1649 _ThrowError("Error in file creation: %", str(err))
1651 return FileStorage(unique_id, children)
1655 constants.LD_LV: LogicalVolume,
1656 constants.LD_DRBD8: DRBD8,
1657 constants.LD_FILE: FileStorage,
1661 def FindDevice(dev_type, unique_id, children):
1662 """Search for an existing, assembled device.
1664 This will succeed only if the device exists and is assembled, but it
1665 does not do any actions in order to activate the device.
1668 if dev_type not in DEV_MAP:
1669 raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
1670 device = DEV_MAP[dev_type](unique_id, children)
1671 if not device.attached:
1676 def Assemble(dev_type, unique_id, children):
1677 """Try to attach or assemble an existing device.
1679 This will attach to assemble the device, as needed, to bring it
1680 fully up. It must be safe to run on already-assembled devices.
1683 if dev_type not in DEV_MAP:
1684 raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
1685 device = DEV_MAP[dev_type](unique_id, children)
1690 def Create(dev_type, unique_id, children, size):
1694 if dev_type not in DEV_MAP:
1695 raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
1696 device = DEV_MAP[dev_type].Create(unique_id, children, size)