Ubuntu Manpage: pvck - Check metadata on physical volumes

Provided by: lvm2_2.03.07-1ubuntu1_amd64

NAME

       pvck - Check metadata on physical volumes

SYNOPSIS

       pvck option_args position_args
           [ option_args ]

           --commandprofile String
           --config String
        -d|--debug
           --driverloaded y|n
           --dump String
        -f|--file String
        -h|--help
           --labelsector Number
           --lockopt String
           --longhelp
           --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
headers
Print header values and warn if any values are incorrect. Checks the label_header, pv_header,
mda_header(s), and metadata text.

metadata
Print or save the current metadata text, using headers to locate the metadata. If headers are damaged,
the metadata may not be found. 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. With --file, the metadata text is saved
to a file.

metadata_all
List or save all versions of metadata found in the metadata area, using headers to locate the metadata.
If headers are damaged, the metadata may not be found. Use --settings "mda_num=2" as above. All
metadata versions are listed (add -v to include descriptions and dates in the listing.) With -file, all
versions are written to a file.

metadata_search
Search for all versions of metadata in the common locations. This does not use headers, so it can find
metadata even when headers are damaged. Use --settings "mda_num=2" as above. All metadata versions are
listed (add -v to include descriptions and dates in the listing.) With --file, all versions are written
to a file. To save one copy of metadata, use --settings "metadata_offset=<offset>", where the offset is
taken from the dump listing.

metadata_area
Save the entire text metadata area to a file without processing.

Repair
--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 had 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
metadata.

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.)

USAGE

       Check for metadata on a device

       pvck PV ...
           [ COMMON_OPTIONS ]
       -

       Check and print LVM headers and metadata on a device

       pvck --dump String 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 ]
           [    --driverloaded y|n ]
           [    --lockopt String ]
           [    --longhelp ]
           [    --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 settings. The String arg uses the same
format as lvm.conf, 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).

--driverloaded y|n
If set to no, the command will not attempt to use device-mapper. For testing and debugging.

--dump String
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, 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.

--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
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.

--nolocking
Disable locking.

--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
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 description.

--settings String
Specifies command specific settings in "Key = Value" form. Repeat this option to specify multiple
values.

-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
unusual 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 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 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
              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, regardless of capitalization, e.g. 'k' and 'K' both refer to 1024.  The default input unit
              is specified  by  letter,  followed  by  |UNIT.   UNIT  represents  other  possible  input  units:
              bBsSkKmMgGtTpPeE.   b|B is bytes, s|S is sectors of 512 bytes, k|K is kilobytes, m|M is megabytes,
              g|G is gigabytes, t|T is terabytes, p|P is petabytes,  e|E  is  exabytes.   (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 suspect 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