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.
642 stat = open(filename, "r")
644 data = stat.read().splitlines()
648 _ThrowError("Can't read any data from %s", filename)
652 def _MassageProcData(data):
653 """Transform the output of _GetProdData into a nicer form.
655 @return: a dictionary of minor: joined lines from /proc/drbd
659 lmatch = re.compile("^ *([0-9]+):.*$")
661 old_minor = old_line = None
663 lresult = lmatch.match(line)
664 if lresult is not None:
665 if old_minor is not None:
666 results[old_minor] = old_line
667 old_minor = int(lresult.group(1))
670 if old_minor is not None:
671 old_line += " " + line.strip()
673 if old_minor is not None:
674 results[old_minor] = old_line
678 def _GetVersion(cls):
679 """Return the DRBD version.
681 This will return a dict with keys:
687 - proto2 (only on drbd > 8.2.X)
690 proc_data = cls._GetProcData()
691 first_line = proc_data[0].strip()
692 version = cls._VERSION_RE.match(first_line)
694 raise errors.BlockDeviceError("Can't parse DRBD version from '%s'" %
697 values = version.groups()
698 retval = {'k_major': int(values[0]),
699 'k_minor': int(values[1]),
700 'k_point': int(values[2]),
701 'api': int(values[3]),
702 'proto': int(values[4]),
704 if values[5] is not None:
705 retval['proto2'] = values[5]
711 """Return the path to a drbd device for a given minor.
714 return "/dev/drbd%d" % minor
717 def GetUsedDevs(cls):
718 """Compute the list of used DRBD devices.
721 data = cls._GetProcData()
724 valid_line = re.compile("^ *([0-9]+): cs:([^ ]+).*$")
726 match = valid_line.match(line)
729 minor = int(match.group(1))
730 state = match.group(2)
731 if state == cls._ST_UNCONFIGURED:
733 used_devs[minor] = state, line
737 def _SetFromMinor(self, minor):
738 """Set our parameters based on the given minor.
740 This sets our minor variable and our dev_path.
744 self.minor = self.dev_path = None
745 self.attached = False
748 self.dev_path = self._DevPath(minor)
752 def _CheckMetaSize(meta_device):
753 """Check if the given meta device looks like a valid one.
755 This currently only check the size, which must be around
759 result = utils.RunCmd(["blockdev", "--getsize", meta_device])
761 logging.error("Failed to get device size: %s - %s",
762 result.fail_reason, result.output)
765 sectors = int(result.stdout)
767 logging.error("Invalid output from blockdev: '%s'", result.stdout)
769 bytes = sectors * 512
770 if bytes < 128 * 1024 * 1024: # less than 128MiB
771 logging.error("Meta device too small (%.2fMib)", (bytes / 1024 / 1024))
773 if bytes > (128 + 32) * 1024 * 1024: # account for an extra (big) PE on LVM
774 logging.error("Meta device too big (%.2fMiB)", (bytes / 1024 / 1024))
778 def Rename(self, new_id):
781 This is not supported for drbd devices.
784 raise errors.ProgrammerError("Can't rename a drbd device")
787 class DRBD8(BaseDRBD):
788 """DRBD v8.x block device.
790 This implements the local host part of the DRBD device, i.e. it
791 doesn't do anything to the supposed peer. If you need a fully
792 connected DRBD pair, you need to use this class on both hosts.
794 The unique_id for the drbd device is the (local_ip, local_port,
795 remote_ip, remote_port) tuple, and it must have two children: the
796 data device and the meta_device. The meta device is checked for
797 valid size and is zeroed on create.
804 _NET_RECONFIG_TIMEOUT = 60
806 def __init__(self, unique_id, children):
807 if children and children.count(None) > 0:
809 super(DRBD8, self).__init__(unique_id, children)
810 self.major = self._DRBD_MAJOR
811 version = self._GetVersion()
812 if version['k_major'] != 8 :
813 _ThrowError("Mismatch in DRBD kernel version and requested ganeti"
814 " usage: kernel is %s.%s, ganeti wants 8.x",
815 version['k_major'], version['k_minor'])
817 if len(children) not in (0, 2):
818 raise ValueError("Invalid configuration data %s" % str(children))
819 if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 6:
820 raise ValueError("Invalid configuration data %s" % str(unique_id))
821 (self._lhost, self._lport,
822 self._rhost, self._rport,
823 self._aminor, self._secret) = unique_id
824 if (self._lhost is not None and self._lhost == self._rhost and
825 self._lport == self._rport):
826 raise ValueError("Invalid configuration data, same local/remote %s" %
831 def _InitMeta(cls, minor, dev_path):
832 """Initialize a meta device.
834 This will not work if the given minor is in use.
837 result = utils.RunCmd(["drbdmeta", "--force", cls._DevPath(minor),
838 "v08", dev_path, "0", "create-md"])
840 _ThrowError("Can't initialize meta device: %s", result.output)
843 def _FindUnusedMinor(cls):
844 """Find an unused DRBD device.
846 This is specific to 8.x as the minors are allocated dynamically,
847 so non-existing numbers up to a max minor count are actually free.
850 data = cls._GetProcData()
852 unused_line = re.compile("^ *([0-9]+): cs:Unconfigured$")
853 used_line = re.compile("^ *([0-9]+): cs:")
856 match = unused_line.match(line)
858 return int(match.group(1))
859 match = used_line.match(line)
861 minor = int(match.group(1))
862 highest = max(highest, minor)
863 if highest is None: # there are no minors in use at all
865 if highest >= cls._MAX_MINORS:
866 logging.error("Error: no free drbd minors!")
867 raise errors.BlockDeviceError("Can't find a free DRBD minor")
871 def _GetShowParser(cls):
872 """Return a parser for `drbd show` output.
874 This will either create or return an already-create parser for the
875 output of the command `drbd show`.
878 if cls._PARSE_SHOW is not None:
879 return cls._PARSE_SHOW
882 lbrace = pyp.Literal("{").suppress()
883 rbrace = pyp.Literal("}").suppress()
884 semi = pyp.Literal(";").suppress()
885 # this also converts the value to an int
886 number = pyp.Word(pyp.nums).setParseAction(lambda s, l, t: int(t[0]))
888 comment = pyp.Literal ("#") + pyp.Optional(pyp.restOfLine)
889 defa = pyp.Literal("_is_default").suppress()
890 dbl_quote = pyp.Literal('"').suppress()
892 keyword = pyp.Word(pyp.alphanums + '-')
895 value = pyp.Word(pyp.alphanums + '_-/.:')
896 quoted = dbl_quote + pyp.CharsNotIn('"') + dbl_quote
897 addr_port = (pyp.Word(pyp.nums + '.') + pyp.Literal(':').suppress() +
899 # meta device, extended syntax
900 meta_value = ((value ^ quoted) + pyp.Literal('[').suppress() +
901 number + pyp.Word(']').suppress())
904 stmt = (~rbrace + keyword + ~lbrace +
905 pyp.Optional(addr_port ^ value ^ quoted ^ meta_value) +
906 pyp.Optional(defa) + semi +
907 pyp.Optional(pyp.restOfLine).suppress())
910 section_name = pyp.Word(pyp.alphas + '_')
911 section = section_name + lbrace + pyp.ZeroOrMore(pyp.Group(stmt)) + rbrace
913 bnf = pyp.ZeroOrMore(pyp.Group(section ^ stmt))
916 cls._PARSE_SHOW = bnf
921 def _GetShowData(cls, minor):
922 """Return the `drbdsetup show` data for a minor.
925 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "show"])
927 logging.error("Can't display the drbd config: %s - %s",
928 result.fail_reason, result.output)
933 def _GetDevInfo(cls, out):
934 """Parse details about a given DRBD minor.
936 This return, if available, the local backing device (as a path)
937 and the local and remote (ip, port) information from a string
938 containing the output of the `drbdsetup show` command as returned
946 bnf = cls._GetShowParser()
950 results = bnf.parseString(out)
951 except pyp.ParseException, err:
952 _ThrowError("Can't parse drbdsetup show output: %s", str(err))
954 # and massage the results into our desired format
955 for section in results:
957 if sname == "_this_host":
958 for lst in section[1:]:
960 data["local_dev"] = lst[1]
961 elif lst[0] == "meta-disk":
962 data["meta_dev"] = lst[1]
963 data["meta_index"] = lst[2]
964 elif lst[0] == "address":
965 data["local_addr"] = tuple(lst[1:])
966 elif sname == "_remote_host":
967 for lst in section[1:]:
968 if lst[0] == "address":
969 data["remote_addr"] = tuple(lst[1:])
972 def _MatchesLocal(self, info):
973 """Test if our local config matches with an existing device.
975 The parameter should be as returned from `_GetDevInfo()`. This
976 method tests if our local backing device is the same as the one in
977 the info parameter, in effect testing if we look like the given
982 backend, meta = self._children
984 backend = meta = None
986 if backend is not None:
987 retval = ("local_dev" in info and info["local_dev"] == backend.dev_path)
989 retval = ("local_dev" not in info)
992 retval = retval and ("meta_dev" in info and
993 info["meta_dev"] == meta.dev_path)
994 retval = retval and ("meta_index" in info and
995 info["meta_index"] == 0)
997 retval = retval and ("meta_dev" not in info and
998 "meta_index" not in info)
1001 def _MatchesNet(self, info):
1002 """Test if our network config matches with an existing device.
1004 The parameter should be as returned from `_GetDevInfo()`. This
1005 method tests if our network configuration is the same as the one
1006 in the info parameter, in effect testing if we look like the given
1010 if (((self._lhost is None and not ("local_addr" in info)) and
1011 (self._rhost is None and not ("remote_addr" in info)))):
1014 if self._lhost is None:
1017 if not ("local_addr" in info and
1018 "remote_addr" in info):
1021 retval = (info["local_addr"] == (self._lhost, self._lport))
1022 retval = (retval and
1023 info["remote_addr"] == (self._rhost, self._rport))
1027 def _AssembleLocal(cls, minor, backend, meta):
1028 """Configure the local part of a DRBD device.
1031 args = ["drbdsetup", cls._DevPath(minor), "disk",
1032 backend, meta, "0", "-e", "detach", "--create-device"]
1033 result = utils.RunCmd(args)
1035 _ThrowError("drbd%d: can't attach local disk: %s", minor, result.output)
1038 def _AssembleNet(cls, minor, net_info, protocol,
1039 dual_pri=False, hmac=None, secret=None):
1040 """Configure the network part of the device.
1043 lhost, lport, rhost, rport = net_info
1044 if None in net_info:
1045 # we don't want network connection and actually want to make
1047 cls._ShutdownNet(minor)
1050 # Workaround for a race condition. When DRBD is doing its dance to
1051 # establish a connection with its peer, it also sends the
1052 # synchronization speed over the wire. In some cases setting the
1053 # sync speed only after setting up both sides can race with DRBD
1054 # connecting, hence we set it here before telling DRBD anything
1056 cls._SetMinorSyncSpeed(minor, constants.SYNC_SPEED)
1058 args = ["drbdsetup", cls._DevPath(minor), "net",
1059 "%s:%s" % (lhost, lport), "%s:%s" % (rhost, rport), protocol,
1060 "-A", "discard-zero-changes",
1067 args.extend(["-a", hmac, "-x", secret])
1068 result = utils.RunCmd(args)
1070 _ThrowError("drbd%d: can't setup network: %s - %s",
1071 minor, result.fail_reason, result.output)
1073 timeout = time.time() + 10
1075 while time.time() < timeout:
1076 info = cls._GetDevInfo(cls._GetShowData(minor))
1077 if not "local_addr" in info or not "remote_addr" in info:
1080 if (info["local_addr"] != (lhost, lport) or
1081 info["remote_addr"] != (rhost, rport)):
1087 _ThrowError("drbd%d: timeout while configuring network", minor)
1089 def AddChildren(self, devices):
1090 """Add a disk to the DRBD device.
1093 if self.minor is None:
1094 _ThrowError("drbd%d: can't attach to dbrd8 during AddChildren",
1096 if len(devices) != 2:
1097 _ThrowError("drbd%d: need two devices for AddChildren", self.minor)
1098 info = self._GetDevInfo(self._GetShowData(self.minor))
1099 if "local_dev" in info:
1100 _ThrowError("drbd%d: already attached to a local disk", self.minor)
1101 backend, meta = devices
1102 if backend.dev_path is None or meta.dev_path is None:
1103 _ThrowError("drbd%d: children not ready during AddChildren", self.minor)
1106 if not self._CheckMetaSize(meta.dev_path):
1107 raise errors.BlockDeviceError("Invalid meta device size")
1108 self._InitMeta(self._FindUnusedMinor(), meta.dev_path)
1110 self._AssembleLocal(self.minor, backend.dev_path, meta.dev_path)
1111 self._children = devices
1113 def RemoveChildren(self, devices):
1114 """Detach the drbd device from local storage.
1117 if self.minor is None:
1118 _ThrowError("drbd%d: can't attach to drbd8 during RemoveChildren",
1120 # early return if we don't actually have backing storage
1121 info = self._GetDevInfo(self._GetShowData(self.minor))
1122 if "local_dev" not in info:
1124 if len(self._children) != 2:
1125 _ThrowError("drbd%d: we don't have two children: %s", self.minor,
1127 if self._children.count(None) == 2: # we don't actually have children :)
1128 logging.warning("drbd%d: requested detach while detached", self.minor)
1130 if len(devices) != 2:
1131 _ThrowError("drbd%d: we need two children in RemoveChildren", self.minor)
1132 for child, dev in zip(self._children, devices):
1133 if dev != child.dev_path:
1134 _ThrowError("drbd%d: mismatch in local storage (%s != %s) in"
1135 " RemoveChildren", self.minor, dev, child.dev_path)
1137 self._ShutdownLocal(self.minor)
1141 def _SetMinorSyncSpeed(cls, minor, kbytes):
1142 """Set the speed of the DRBD syncer.
1144 This is the low-level implementation.
1147 @param minor: the drbd minor whose settings we change
1149 @param kbytes: the speed in kbytes/second
1151 @return: the success of the operation
1154 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "syncer",
1155 "-r", "%d" % kbytes, "--create-device"])
1157 logging.error("Can't change syncer rate: %s - %s",
1158 result.fail_reason, result.output)
1159 return not result.failed
1161 def SetSyncSpeed(self, kbytes):
1162 """Set the speed of the DRBD syncer.
1165 @param kbytes: the speed in kbytes/second
1167 @return: the success of the operation
1170 if self.minor is None:
1171 logging.info("Not attached during SetSyncSpeed")
1173 children_result = super(DRBD8, self).SetSyncSpeed(kbytes)
1174 return self._SetMinorSyncSpeed(self.minor, kbytes) and children_result
1176 def GetProcStatus(self):
1177 """Return device data from /proc.
1180 if self.minor is None:
1181 _ThrowError("drbd%d: GetStats() called while not attached", self._aminor)
1182 proc_info = self._MassageProcData(self._GetProcData())
1183 if self.minor not in proc_info:
1184 _ThrowError("drbd%d: can't find myself in /proc", self.minor)
1185 return DRBD8Status(proc_info[self.minor])
1187 def GetSyncStatus(self):
1188 """Returns the sync status of the device.
1191 If sync_percent is None, it means all is ok
1192 If estimated_time is None, it means we can't esimate
1193 the time needed, otherwise it's the time left in seconds.
1196 We set the is_degraded parameter to True on two conditions:
1197 network not connected or local disk missing.
1199 We compute the ldisk parameter based on wheter we have a local
1203 @return: (sync_percent, estimated_time, is_degraded, ldisk)
1206 if self.minor is None and not self.Attach():
1207 _ThrowError("drbd%d: can't Attach() in GetSyncStatus", self._aminor)
1208 stats = self.GetProcStatus()
1209 ldisk = not stats.is_disk_uptodate
1210 is_degraded = not stats.is_connected
1211 return stats.sync_percent, stats.est_time, is_degraded or ldisk, ldisk
1213 def Open(self, force=False):
1214 """Make the local state primary.
1216 If the 'force' parameter is given, the '-o' option is passed to
1217 drbdsetup. Since this is a potentially dangerous operation, the
1218 force flag should be only given after creation, when it actually
1222 if self.minor is None and not self.Attach():
1223 logging.error("DRBD cannot attach to a device during open")
1225 cmd = ["drbdsetup", self.dev_path, "primary"]
1228 result = utils.RunCmd(cmd)
1230 _ThrowError("drbd%d: can't make drbd device primary: %s", self.minor,
1234 """Make the local state secondary.
1236 This will, of course, fail if the device is in use.
1239 if self.minor is None and not self.Attach():
1240 _ThrowError("drbd%d: can't Attach() in Close()", self._aminor)
1241 result = utils.RunCmd(["drbdsetup", self.dev_path, "secondary"])
1243 _ThrowError("drbd%d: can't switch drbd device to secondary: %s",
1244 self.minor, result.output)
1246 def DisconnectNet(self):
1247 """Removes network configuration.
1249 This method shutdowns the network side of the device.
1251 The method will wait up to a hardcoded timeout for the device to
1252 go into standalone after the 'disconnect' command before
1253 re-configuring it, as sometimes it takes a while for the
1254 disconnect to actually propagate and thus we might issue a 'net'
1255 command while the device is still connected. If the device will
1256 still be attached to the network and we time out, we raise an
1260 if self.minor is None:
1261 _ThrowError("drbd%d: disk not attached in re-attach net", self._aminor)
1263 if None in (self._lhost, self._lport, self._rhost, self._rport):
1264 _ThrowError("drbd%d: DRBD disk missing network info in"
1265 " DisconnectNet()", self.minor)
1267 ever_disconnected = _IgnoreError(self._ShutdownNet, self.minor)
1268 timeout_limit = time.time() + self._NET_RECONFIG_TIMEOUT
1269 sleep_time = 0.100 # we start the retry time at 100 miliseconds
1270 while time.time() < timeout_limit:
1271 status = self.GetProcStatus()
1272 if status.is_standalone:
1274 # retry the disconnect, it seems possible that due to a
1275 # well-time disconnect on the peer, my disconnect command might
1276 # be ingored and forgotten
1277 ever_disconnected = _IgnoreError(self._ShutdownNet, self.minor) or \
1279 time.sleep(sleep_time)
1280 sleep_time = min(2, sleep_time * 1.5)
1282 if not status.is_standalone:
1283 if ever_disconnected:
1284 msg = ("drbd%d: device did not react to the"
1285 " 'disconnect' command in a timely manner")
1287 msg = "drbd%d: can't shutdown network, even after multiple retries"
1288 _ThrowError(msg, self.minor)
1290 reconfig_time = time.time() - timeout_limit + self._NET_RECONFIG_TIMEOUT
1291 if reconfig_time > 15: # hardcoded alert limit
1292 logging.info("drbd%d: DisconnectNet: detach took %.3f seconds",
1293 self.minor, reconfig_time)
1295 def AttachNet(self, multimaster):
1296 """Reconnects the network.
1298 This method connects the network side of the device with a
1299 specified multi-master flag. The device needs to be 'Standalone'
1300 but have valid network configuration data.
1303 - multimaster: init the network in dual-primary mode
1306 if self.minor is None:
1307 _ThrowError("drbd%d: device not attached in AttachNet", self._aminor)
1309 if None in (self._lhost, self._lport, self._rhost, self._rport):
1310 _ThrowError("drbd%d: missing network info in AttachNet()", self.minor)
1312 status = self.GetProcStatus()
1314 if not status.is_standalone:
1315 _ThrowError("drbd%d: device is not standalone in AttachNet", self.minor)
1317 self._AssembleNet(self.minor,
1318 (self._lhost, self._lport, self._rhost, self._rport),
1319 constants.DRBD_NET_PROTOCOL, dual_pri=multimaster,
1320 hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
1323 """Check if our minor is configured.
1325 This doesn't do any device configurations - it only checks if the
1326 minor is in a state different from Unconfigured.
1328 Note that this function will not change the state of the system in
1329 any way (except in case of side-effects caused by reading from
1333 used_devs = self.GetUsedDevs()
1334 if self._aminor in used_devs:
1335 minor = self._aminor
1339 self._SetFromMinor(minor)
1340 return minor is not None
1343 """Assemble the drbd.
1346 - if we have a configured device, we try to ensure that it matches
1348 - if not, we create it from zero
1351 super(DRBD8, self).Assemble()
1354 if self.minor is None:
1355 # local device completely unconfigured
1356 self._FastAssemble()
1358 # we have to recheck the local and network status and try to fix
1360 self._SlowAssemble()
1362 def _SlowAssemble(self):
1363 """Assembles the DRBD device from a (partially) configured device.
1365 In case of partially attached (local device matches but no network
1366 setup), we perform the network attach. If successful, we re-test
1367 the attach if can return success.
1370 net_data = (self._lhost, self._lport, self._rhost, self._rport)
1371 for minor in (self._aminor,):
1372 info = self._GetDevInfo(self._GetShowData(minor))
1373 match_l = self._MatchesLocal(info)
1374 match_r = self._MatchesNet(info)
1376 if match_l and match_r:
1377 # everything matches
1380 if match_l and not match_r and "local_addr" not in info:
1381 # disk matches, but not attached to network, attach and recheck
1382 self._AssembleNet(minor, net_data, constants.DRBD_NET_PROTOCOL,
1383 hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
1384 if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
1387 _ThrowError("drbd%d: network attach successful, but 'drbdsetup"
1388 " show' disagrees", minor)
1390 if match_r and "local_dev" not in info:
1391 # no local disk, but network attached and it matches
1392 self._AssembleLocal(minor, self._children[0].dev_path,
1393 self._children[1].dev_path)
1394 if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
1397 _ThrowError("drbd%d: disk attach successful, but 'drbdsetup"
1398 " show' disagrees", minor)
1400 # this case must be considered only if we actually have local
1401 # storage, i.e. not in diskless mode, because all diskless
1402 # devices are equal from the point of view of local
1404 if (match_l and "local_dev" in info and
1405 not match_r and "local_addr" in info):
1406 # strange case - the device network part points to somewhere
1407 # else, even though its local storage is ours; as we own the
1408 # drbd space, we try to disconnect from the remote peer and
1409 # reconnect to our correct one
1411 self._ShutdownNet(minor)
1412 except errors.BlockDeviceError, err:
1413 _ThrowError("Device has correct local storage, wrong remote peer"
1414 " and is unable to disconnect in order to attach to"
1415 " the correct peer: %s", str(err))
1416 # note: _AssembleNet also handles the case when we don't want
1417 # local storage (i.e. one or more of the _[lr](host|port) is
1419 self._AssembleNet(minor, net_data, constants.DRBD_NET_PROTOCOL,
1420 hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
1421 if self._MatchesNet(self._GetDevInfo(self._GetShowData(minor))):
1424 _ThrowError("drbd%d: network attach successful, but 'drbdsetup"
1425 " show' disagrees", minor)
1430 self._SetFromMinor(minor)
1432 _ThrowError("drbd%d: cannot activate, unknown or unhandled reason",
1435 def _FastAssemble(self):
1436 """Assemble the drbd device from zero.
1438 This is run when in Assemble we detect our minor is unused.
1441 minor = self._aminor
1442 if self._children and self._children[0] and self._children[1]:
1443 self._AssembleLocal(minor, self._children[0].dev_path,
1444 self._children[1].dev_path)
1445 if self._lhost and self._lport and self._rhost and self._rport:
1446 self._AssembleNet(minor,
1447 (self._lhost, self._lport, self._rhost, self._rport),
1448 constants.DRBD_NET_PROTOCOL,
1449 hmac=constants.DRBD_HMAC_ALG, secret=self._secret)
1450 self._SetFromMinor(minor)
1453 def _ShutdownLocal(cls, minor):
1454 """Detach from the local device.
1456 I/Os will continue to be served from the remote device. If we
1457 don't have a remote device, this operation will fail.
1460 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "detach"])
1462 _ThrowError("drbd%d: can't detach local disk: %s", minor, result.output)
1465 def _ShutdownNet(cls, minor):
1466 """Disconnect from the remote peer.
1468 This fails if we don't have a local device.
1471 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "disconnect"])
1473 _ThrowError("drbd%d: can't shutdown network: %s", minor, result.output)
1476 def _ShutdownAll(cls, minor):
1477 """Deactivate the device.
1479 This will, of course, fail if the device is in use.
1482 result = utils.RunCmd(["drbdsetup", cls._DevPath(minor), "down"])
1484 _ThrowError("Can't shutdown drbd device: %s", result.output)
1487 """Shutdown the DRBD device.
1490 if self.minor is None and not self.Attach():
1491 logging.info("drbd%d: not attached during Shutdown()", self._aminor)
1495 self.dev_path = None
1496 self._ShutdownAll(minor)
1499 """Stub remove for DRBD devices.
1505 def Create(cls, unique_id, children, size):
1506 """Create a new DRBD8 device.
1508 Since DRBD devices are not created per se, just assembled, this
1509 function only initializes the metadata.
1512 if len(children) != 2:
1513 raise errors.ProgrammerError("Invalid setup for the drbd device")
1514 # check that the minor is unused
1515 aminor = unique_id[4]
1516 proc_info = cls._MassageProcData(cls._GetProcData())
1517 if aminor in proc_info:
1518 status = DRBD8Status(proc_info[aminor])
1519 in_use = status.is_in_use
1523 _ThrowError("DRBD minor %d already in use at Create() time", aminor)
1526 if not meta.Attach():
1527 raise errors.BlockDeviceError("Can't attach to meta device")
1528 if not cls._CheckMetaSize(meta.dev_path):
1529 raise errors.BlockDeviceError("Invalid meta device size")
1530 cls._InitMeta(aminor, meta.dev_path)
1531 return cls(unique_id, children)
1533 def Grow(self, amount):
1534 """Resize the DRBD device and its backing storage.
1537 if self.minor is None:
1538 _ThrowError("drbd%d: Grow called while not attached", self._aminor)
1539 if len(self._children) != 2 or None in self._children:
1540 _ThrowError("drbd%d: cannot grow diskless device", self.minor)
1541 self._children[0].Grow(amount)
1542 result = utils.RunCmd(["drbdsetup", self.dev_path, "resize"])
1544 _ThrowError("drbd%d: resize failed: %s", self.minor, result.output)
1547 class FileStorage(BlockDev):
1550 This class represents the a file storage backend device.
1552 The unique_id for the file device is a (file_driver, file_path) tuple.
1555 def __init__(self, unique_id, children):
1556 """Initalizes a file device backend.
1560 raise errors.BlockDeviceError("Invalid setup for file device")
1561 super(FileStorage, self).__init__(unique_id, children)
1562 if not isinstance(unique_id, (tuple, list)) or len(unique_id) != 2:
1563 raise ValueError("Invalid configuration data %s" % str(unique_id))
1564 self.driver = unique_id[0]
1565 self.dev_path = unique_id[1]
1569 """Assemble the device.
1571 Checks whether the file device exists, raises BlockDeviceError otherwise.
1574 if not os.path.exists(self.dev_path):
1575 _ThrowError("File device '%s' does not exist" % self.dev_path)
1578 """Shutdown the device.
1580 This is a no-op for the file type, as we don't deacivate
1581 the file on shutdown.
1586 def Open(self, force=False):
1587 """Make the device ready for I/O.
1589 This is a no-op for the file type.
1595 """Notifies that the device will no longer be used for I/O.
1597 This is a no-op for the file type.
1603 """Remove the file backing the block device.
1606 @return: True if the removal was successful
1610 os.remove(self.dev_path)
1611 except OSError, err:
1612 if err.errno != errno.ENOENT:
1613 _ThrowError("Can't remove file '%s': %s", self.dev_path, err)
1616 """Attach to an existing file.
1618 Check if this file already exists.
1621 @return: True if file exists
1624 self.attached = os.path.exists(self.dev_path)
1625 return self.attached
1628 def Create(cls, unique_id, children, size):
1629 """Create a new file.
1631 @param size: the size of file in MiB
1633 @rtype: L{bdev.FileStorage}
1634 @return: an instance of FileStorage
1637 # TODO: decide whether we should check for existing files and
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]
1643 f = open(dev_path, 'w')
1644 f.truncate(size * 1024 * 1024)
1646 except IOError, err:
1647 _ThrowError("Error in file creation: %", str(err))
1649 return FileStorage(unique_id, children)
1653 constants.LD_LV: LogicalVolume,
1654 constants.LD_DRBD8: DRBD8,
1655 constants.LD_FILE: FileStorage,
1659 def FindDevice(dev_type, unique_id, children):
1660 """Search for an existing, assembled device.
1662 This will succeed only if the device exists and is assembled, but it
1663 does not do any actions in order to activate the device.
1666 if dev_type not in DEV_MAP:
1667 raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
1668 device = DEV_MAP[dev_type](unique_id, children)
1669 if not device.attached:
1674 def Assemble(dev_type, unique_id, children):
1675 """Try to attach or assemble an existing device.
1677 This will attach to assemble the device, as needed, to bring it
1678 fully up. It must be safe to run on already-assembled devices.
1681 if dev_type not in DEV_MAP:
1682 raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
1683 device = DEV_MAP[dev_type](unique_id, children)
1688 def Create(dev_type, unique_id, children, size):
1692 if dev_type not in DEV_MAP:
1693 raise errors.ProgrammerError("Invalid block device type '%s'" % dev_type)
1694 device = DEV_MAP[dev_type].Create(unique_id, children, size)