# pvck

## 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 optionally exist near the end of the device.
           The metadata text exists in an area (about 1MiB by default)  imme‐
           diately  following  the  mda_header  sector.  The metadata 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, using
           headers to locate metadata.  Full copies of all metadata are saved
           to a file with the --file option.  If headers are damaged, metada‐
           ta  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  metadata,  use
           --settings  "metadata_offset=<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
           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 damaged,
           if  using an old metadata version, or if a backup file is used in‐
           stead 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 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
           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 speci‐
           fied,  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 loca‐
           tion 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)
                  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.   de‐
                  bug: 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 different
                  sector near the start of the disk (between 0 and  3  inclu‐
                  sive  -  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 com‐
                  mand  may  read more devices to find PVs when hints are not
                  used. The command will still perform standard hint file in‐
                  validation where appropriate.
    
           **--nolocking**
                  Disable locking.
    
           **--profile** _String_
                  An alias for --commandprofile or --metadataprofile, depend‐
                  ing on the command.
    
           **--**[**pv**]**metadatacopies 0** |**1** |**2**
                  The number of metadata areas to set aside on a PV for stor‐
                  ing 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 meta‐
                  data 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  descrip‐
                  tion.
    
           **--settings** _String_
                  Specifies  command specific settings in "Key = Value" form.
                  Combine 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 never‐
                  theless 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 as‐
                  sume the answer yes. Use with extreme caution.  (For  auto‐
                  matic no, see -qq.)
    


## VARIABLES



           _PV_     Physical Volume name, a device path under /dev.  For com‐
                  mands managing physical extents, a PV positional arg gener‐
                  ally 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.  In‐
                  put 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: **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
           suspect there was an LVM partition at approximately 100 MiB, then
           this area of the disk can be scanned using the **--labelsector** para‐
           meter with a value of 204800 (100 * 1024 * 1024 / 512 = 204800).
           **pvck --labelsector 204800 /dev/sda**
    


* * *