pvck(8) — Linux manual page
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_head‐
er, 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 de‐
vice. An mda_header exists in a 512 byte sector at offset 4096
bytes. A second mda_header can optionally 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 meta‐
data text is checked but not printed (see other options).
metadata
Print the current LVM VG metadata text (or save to a file), using
headers 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, us‐
ing 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 versions.
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 metada‐
ta, use --settings "metadata_offset=<offset>", where the offset
is taken from the list of versions found. Use -v to include de‐
scriptions 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 being 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 determine 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 re‐
pair. 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 dam‐
aged, if using an old metadata version, or if a backup file is
used instead of raw metadata (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 la‐
bel_header.
--repairtype metadata
Repairs the mda_header and metadata text. It requires the head‐
ers 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 re‐
pair behaviors. 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
metadata 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 default.) 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 in‐
cludes 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 spec‐
ified, repair will attempt to determine the correct PV UUID by
matching a device 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 fol‐
lows 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) settings. The String arg uses the same format
as lvm.conf(5), or may use section/field syntax. See
lvm.conf(5) for more information 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
Devices that the command can use. This option can be re‐
peated or accepts a comma separated list of devices. 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) command. This overrides the lvm.conf(5) de‐
vices/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 re‐
pair. Option values include: headers to print and check
LVM headers, metadata to print or save the current text
metadata, metadata_all to list or save all versions of
metadata, metadata_search to list or save all versions of
metadata, searching standard locations in case of damaged
headers, metadata_area to save an entire 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 informa‐
tion is in addition to information enabled by the lvm.conf
log/journal setting. command: record information about
the command. output: record the default command output.
debug: record full command debugging.
--labelsector Number
By default the PV is labelled with an LVM2 identifier in
its second sector (sector 1). This lets you use a differ‐
ent sector near the start of the disk (between 0 and 3 in‐
clusive - see LABEL_SCAN_SECTORS in the source). Use with
care.
--lockopt String
Used to pass options for special cases to lvmlockd. See
lvmlockd(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.
--profile String
An alias for --commandprofile or --metadataprofile, de‐
pending 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 use‐
ful in VGs containing many PVs (this places limitations on
the ability to use vgsplit later.)
-q|--quiet ...
Suppress output and log messages. Overrides --debug and
--verbose. 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 descrip‐
tion.
--settings String
Specifies command specific settings in "Key = Value" form.
Combine multiple settings in quotes, or repeat the set‐
tings option for each.
-t|--test
Run in test mode. Commands will not update metadata. This
is implemented by disabling all metadata writing but nev‐
ertheless returning success to the calling function. This
may lead to unusual error messages in multi-stage opera‐
tions if a tool relies on reading back metadata it be‐
lieves has changed but hasn't.
-v|--verbose ...
Set verbose level. Repeat from 1 to 4 times to increase
the detail 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 au‐
tomatic no, see -qq.)
VARIABLES
PV Physical Volume name, a device path under /dev. For com‐
mands managing physical extents, a PV positional arg gen‐
erally accepts a suffix indicating a range (or multiple
ranges) of physical extents (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 content.
Size[UNIT]
Size is an input number that accepts an optional unit.
Input units are always treated as base two values, regard‐
less of capitalization, e.g. 'k' and 'K' both refer to
1024. The default input unit is specified by letter, fol‐
lowed by |UNIT. UNIT represents 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 con‐
trol --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
suspect there was an LVM partition at approximately 100 MiB, then
this area of the disk can be scanned using the --labelsector pa‐
rameter 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), lvmcache(7), lvmraid(7),
lvmthin(7), lvmvdo(7), lvmautoactivation(7)
COLOPHON
This page is part of the lvm2 (Logical Volume Manager 2) project.
Information about the project can be found at
⟨http://www.sourceware.org/lvm2/⟩. If you have a bug report for
this manual page, see ⟨https://github.com/lvmteam/lvm2/issues⟩.
This page was obtained from the project's upstream Git repository
⟨git://sourceware.org/git/lvm2.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-11.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Red Hat, Inc. LVM TOOLS 2.03.25(2)-git (2024-05-16) PVCK(8)
Pages that refer to this page: lvchange(8), lvconvert(8), lvcreate(8), lvdisplay(8), lvextend(8), lvm(8), lvmconfig(8), lvmdevices(8), lvmdiskscan(8), lvm-fullreport(8), lvm-lvpoll(8), lvreduce(8), lvremove(8), lvrename(8), lvresize(8), lvs(8), lvscan(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), vgconvert(8), vgcreate(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)