PVCK(8) System Manager's Manual PVCK(8)
NAME
pvck — Check metadata on physical volumes
SYNOPSIS
pvck option_args position_args
[ option_args ]
--commandprofile String
--config String
-d|--debug
--devices PV
--devicesfile String
--driverloaded y|n
--dump headers|metadata|metadata_all|metadata_search
-f|--file String
-h|--help
--journal String
--labelsector Number
--lockopt String
--longhelp
--nohints
--nolocking
--profile String
--[pv]metadatacopies 0|1|2
-q|--quiet
--repair
--repairtype pv_header|metadata|label_header
--settings String
-t|--test
-v|--verbose
--version
-y|--yes
DESCRIPTION
pvck checks and repairs LVM metadata on PVs.
Dump options
headers
Print LVM on-disk headers and structures: label_header, pv_header,
mda_header(s), and metadata text. Warnings are printed if any values
are incorrect. The label_header and pv_header both exist in a 512 byte
sector, usually the second sector of the device. An mda_header exists
in a 512 byte sector at offset 4096 bytes. A second mda_header can op-
tionally exist near the end of the device. The metadata text exists in
an area (about 1MiB by default) immediately following the mda_header
sector. The metadata text is checked but not printed (see other op-
tions).
metadata
Print the current LVM VG metadata text (or save to a file), using head-
ers to locate the latest copy of metadata. If headers are damaged,
metadata may not be found (see metadata_search). Use --settings
"mda_num=2" to look in mda2 (the second mda at the end of the device,
if used). The metadata text is printed to stdout or saved to a file
with --file.
metadata_all
List all versions of VG metadata found in the metadata area, using
headers to locate metadata. Full copies of all metadata are saved to a
file with the --file option. If headers are damaged, metadata may not
be found (see metadata_search). Use --settings "mda_num=2" as above.
Use -v to include descriptions and dates when listing metadata ver-
sions.
metadata_search
List all versions of VG metadata found in the metadata area, searching
common locations so metadata can be found if headers are damaged. Full
copies of all metadata are saved to a file with the --file option. To
save one specific version of metadata, use --settings "metadata_off-
set=<offset>", where the offset is taken from the list of versions
found. Use -v to include descriptions and dates when listing metadata
versions.
metadata_area
Save the entire text metadata area to a file without processing.
Repair options
--repair
Repair headers and metadata on a PV. This uses a metadata input file
that was extracted by --dump, or a backup file (from /etc/lvm/backup).
When possible, use metadata saved by --dump from another PV in the same
VG (or from a second metadata area on the PV).
There are cases where the PV UUID needs to be specified for the PV be-
ing repaired. It is specified using --settings "pv_uuid=<UUID>". In
particular, if the device name for the PV being repaired does not match
the previous device name of the PV, then LVM may not be able to deter-
mine the correct PV UUID. When headers are damaged on more than one PV
in a VG, it is important for the user to determine the correct PV UUID
and specify it in --settings. Otherwise, the wrong PV UUID could be
used if device names have been swapped since the metadata was last
written.
If a PV has no metadata areas and the pv_header is damaged, then the
repair will not know to create no metadata areas during repair. It
will by default repair metadata in mda1. To repair with no metadata
areas, use --settings "mda_offset=0 mda_size=0".
There are cases where repair should be run on all PVs in the VG (using
the same metadata file): if all PVs in the VG are damaged, if using an
old metadata version, or if a backup file is used instead of raw meta-
data (taken from pvck dump.)
Using --repair is equivalent to running --repairtype pv_header followed
by --repairtype metadata.
--repairtype pv_header
Repairs the header sector, containing the pv_header and label_header.
--repairtype metadata
Repairs the mda_header and metadata text. It requires the headers to
be correct (having been undamaged or already repaired).
--repairtype label_header
Repairs label_header fields, leaving the pv_header (in the same sector)
unchanged. (repairtype pv_header should usually be used instead.)
Settings
The --settings option controls or overrides certain dump or repair be-
haviors. All offset and size values in settings are in bytes (units
are not recognized.) These settings are subject to change.
mda_num=1|2
Select which metadata area should be used. By default the first meta-
data area (1) is used. mda1 is always located at offset 4096. mda2,
at the end of the device, often does not exist (it's not created by de-
fault.) If mda1 is erased, mda2, if it exists, will often still have
metadata.
metadata_offset=bytes
Select metadata text at this offset. Use with metadata_search to
print/save one instance of metadata text.
mda_offset=bytes mda_size=bytes
Refers to a metadata area (mda) location and size. An mda includes an
mda_header and circular metadata text buffer. Setting this forces
metadata_search look for metadata in the given area instead of the
standard locations. When set to zero with repair, it indicates no
metadata areas should exist.
mda2_offset=bytes mda2_size=bytes
When repairing a pv_header, this forces a specific offset and size for
mda2 that should be recorded in the pv_header.
pv_uuid=uuid
Specify the PV UUID of the device being repaired. When not specified,
repair will attempt to determine the correct PV UUID by matching a de-
vice name in the metadata.
device_size=bytes
data_offset=bytes
When repairing a pv_header, the device_size, data_offset, and pvid can
all be specified directly, in which case these values are not taken
from a metadata file (where they usually come from), and the metadata
file can be omitted. data_offset is the starting location of the first
physical extent (data), which follows the first metadata area.
USAGE
Check for metadata on a device
pvck PV ...
[ COMMON_OPTIONS ]
—
Check and print LVM headers and metadata on a device
pvck --dump headers|metadata|metadata_all|metadata_search PV
[ -f|--file String ]
[ --settings String ]
[ --[pv]metadatacopies 0|1|2 ]
[ COMMON_OPTIONS ]
—
Repair LVM headers or metadata on a device
pvck --repairtype pv_header|metadata|label_header PV
[ -f|--file String ]
[ --settings String ]
[ COMMON_OPTIONS ]
—
Repair LVM headers and metadata on a device
pvck --repair -f|--file String PV
[ --settings String ]
[ COMMON_OPTIONS ]
—
Common options for command:
[ --labelsector Number ]
Common options for lvm:
[ -d|--debug ]
[ -h|--help ]
[ -q|--quiet ]
[ -t|--test ]
[ -v|--verbose ]
[ -y|--yes ]
[ --commandprofile String ]
[ --config String ]
[ --devices PV ]
[ --devicesfile String ]
[ --driverloaded y|n ]
[ --journal String ]
[ --lockopt String ]
[ --longhelp ]
[ --nohints ]
[ --nolocking ]
[ --profile String ]
[ --version ]
OPTIONS
--commandprofile String
The command profile to use for command configuration. See
lvm.conf(5) for more information about profiles.
--config String
Config settings for the command. These override lvm.conf(5) set-
tings. The String arg uses the same format as lvm.conf(5), or
may use section/field syntax. See lvm.conf(5) for more informa-
tion about config.
-d|--debug ...
Set debug level. Repeat from 1 to 6 times to increase the detail
of messages sent to the log file and/or syslog (if configured).
--devices PV
Restricts the devices that are visible and accessible to the
command. Devices not listed will appear to be missing. This op-
tion can be repeated, or accepts a comma separated list of de-
vices. This overrides the devices file.
--devicesfile String
A file listing devices that LVM should use. The file must exist
in /etc/lvm/devices/ and is managed with the lvmdevices(8) com-
mand. This overrides the lvm.conf(5) devices/devicesfile and
devices/use_devicesfile settings.
--driverloaded y|n
If set to no, the command will not attempt to use device-mapper.
For testing and debugging.
--dump headers|metadata|metadata_all|metadata_search
Dump headers and metadata from a PV for debugging and repair.
Option values include: headers to print and check LVM headers,
metadata to print or save the current text metadata, metada-
ta_all to list or save all versions of metadata, metadata_search
to list or save all versions of metadata, searching standard lo-
cations in case of damaged headers, metadata_area to save an en-
tire text metadata area to a file.
-f|--file String
Metadata file to read or write.
-h|--help
Display help text.
--journal String
Record information in the systemd journal. This information is
in addition to information enabled by the lvm.conf log/journal
setting. command: record information about the command. out-
put: record the default command output. debug: record full com-
mand debugging.
--labelsector Number
By default the PV is labelled with an LVM2 identifier in its
second sector (sector 1). This lets you use a different sector
near the start of the disk (between 0 and 3 inclusive - see LA-
BEL_SCAN_SECTORS in the source). Use with care.
--lockopt String
Used to pass options for special cases to lvmlockd. See lvm-
lockd(8) for more information.
--longhelp
Display long help text.
--nohints
Do not use the hints file to locate devices for PVs. A command
may read more devices to find PVs when hints are not used. The
command will still perform standard hint file invalidation where
appropriate.
--nolocking
Disable locking. Use with caution, concurrent commands may pro-
duce incorrect results.
--profile String
An alias for --commandprofile or --metadataprofile, depending on
the command.
--[pv]metadatacopies 0|1|2
The number of metadata areas to set aside on a PV for storing VG
metadata. When 2, one copy of the VG metadata is stored at the
front of the PV and a second copy is stored at the end. When 1,
one copy of the VG metadata is stored at the front of the PV.
When 0, no copies of the VG metadata are stored on the given PV.
This may be useful in VGs containing many PVs (this places limi-
tations on the ability to use vgsplit later.)
-q|--quiet ...
Suppress output and log messages. Overrides --debug and --ver-
bose. Repeat once to also suppress any prompts with answer
'no'.
--repair
Repair headers and metadata on a PV.
--repairtype pv_header|metadata|label_header
Repair headers and metadata on a PV. See command description.
--settings String
Specifies command specific settings in "Key = Value" form. Com-
bine multiple settings in quotes, or repeat the settings option
for each.
-t|--test
Run in test mode. Commands will not update metadata. This is
implemented by disabling all metadata writing but nevertheless
returning success to the calling function. This may lead to un-
usual error messages in multi-stage operations if a tool relies
on reading back metadata it believes has changed but hasn't.
-v|--verbose ...
Set verbose level. Repeat from 1 to 4 times to increase the de-
tail of messages sent to stdout and stderr.
--version
Display version information.
-y|--yes
Do not prompt for confirmation interactively but always assume
the answer yes. Use with extreme caution. (For automatic no,
see -qq.)
VARIABLES
PV Physical Volume name, a device path under /dev. For commands
managing physical extents, a PV positional arg generally accepts
a suffix indicating a range (or multiple ranges) of physical ex-
tents (PEs). When the first PE is omitted, it defaults to the
start of the device, and when the last PE is omitted it defaults
to end. Start and end range (inclusive): PV[:PE-PE]... Start
and length range (counting from 0): PV[:PE+PE]...
String See the option description for information about the string con-
tent.
Size[UNIT]
Size is an input number that accepts an optional unit. Input
units are always treated as base two values, regardless of capi-
talization, e.g. 'k' and 'K' both refer to 1024. The default
input unit is specified by letter, followed by |UNIT. UNIT rep-
resents other possible input units: b|B is bytes, s|S is sectors
of 512 bytes, k|K is KiB, m|M is MiB, g|G is GiB, t|T is TiB,
p|P is PiB, e|E is EiB. (This should not be confused with the
output control --units, where capital letters mean multiple of
1000.)
ENVIRONMENT VARIABLES
See lvm(8) for information about environment variables used by lvm.
For example, LVM_VG_NAME can generally be substituted for a required VG
parameter.
EXAMPLES
If the partition table is corrupted or lost on /dev/sda, and you sus-
pect there was an LVM partition at approximately 100 MiB, then this
area of the disk can be scanned using the --labelsector parameter with
a value of 204800 (100 * 1024 * 1024 / 512 = 204800).
pvck --labelsector 204800 /dev/sda
SEE ALSO
lvm(8), lvm.conf(5), lvmconfig(8), lvmdevices(8),
pvchange(8), pvck(8), pvcreate(8), pvdisplay(8), pvmove(8),
pvremove(8), pvresize(8), pvs(8), pvscan(8),
vgcfgbackup(8), vgcfgrestore(8), vgchange(8), vgck(8), vgcreate(8),
vgconvert(8), vgdisplay(8), vgexport(8), vgextend(8), vgimport(8),
vgimportclone(8), vgimportdevices(8), vgmerge(8), vgmknodes(8),
vgreduce(8), vgremove(8), vgrename(8), vgs(8), vgscan(8), vgsplit(8),
lvcreate(8), lvchange(8), lvconvert(8), lvdisplay(8), lvextend(8),
lvreduce(8), lvremove(8), lvrename(8), lvresize(8), lvs(8), lvscan(8),
lvm-fullreport(8), lvm-lvpoll(8), blkdeactivate(8), lvmdump(8),
dmeventd(8), lvmpolld(8), lvmlockd(8), lvmlockctl(8), cmirrord(8),
lvmdbusd(8), fsadm(8),
lvmsystemid(7), lvmreport(7), lvmraid(7), lvmthin(7), lvmcache(7)
Red Hat, Inc. LVM TOOLS 2.03.16(2) (2022-05-18) PVCK(8)
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