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PVSCAN(8)                   System Manager's Manual                  PVSCAN(8)

NAME
       pvscan - List all physical volumes
SYNOPSIS
       pvscan option_args
           [ option_args ]
           [ position_args ]
DESCRIPTION
       pvscan scans all supported LVM block devices in the system for PVs.
       Scanning with lvmetad
       pvscan operates differently when used with the lvmetad(8) daemon.
       Scanning  disks  is required to read LVM metadata and identify LVM PVs.
       Once read, lvmetad caches the metadata so that LVM commands can read it
       without  repeatedly  scanning  disks.  This is helpful because scanning
       disks is time consuming, and frequent scanning may interfere  with  the
       normal work of the system and disks.
       When lvmetad is not used, LVM commands revert to scanning disks to read
       metadata.  Any LVM command that needs metadata will scan disks for  it;
       running  the  pvscan command is not necessary for the sake of other LVM
       commands.
       When lvmetad is used, LVM commands  avoid  scanning  disks  by  reading
       metadata  from lvmetad.  When new disks appear, they must be scanned so
       their metadata can be cached in lvmetad.  This is done by  the  command
       pvscan --cache, which scans disks and passes the metadata to lvmetad.
       The  pvscan  --cache  command  is typically run automatically by system
       services when a new device appears.  Users do not generally need to run
       this command if the system and lvmetad are running properly.
       Many  scripts  contain unnecessary pvscan (or vgscan) commands for his-
       torical reasons.  To avoid disrupting the system with  extraneous  disk
       scanning,  an  ordinary pvscan (without --cache) will simply read meta-
       data from lvmetad like other LVM commands.  It  does  not  do  anything
       beyond displaying the current state of the cache.
       o When  given  specific device name arguments, pvscan --cache will only
         read the named devices.
       o LVM udev rules and systemd services are used  to  initiate  automatic
         device scanning.
       o To  prevent devices from being scanned by pvscan --cache, add them to
         lvm.conf(5) devices/global_filter.  The devices/filter  setting  does
         not apply to system level scanning.  For more information, see:
         lvmconfig --withcomments devices/global_filter
       o If  lvmetad  is started or restarted after devices are visible, or if
         the global_filter has changed, then all devices must be rescanned for
         metadata with the command pvscan --cache.
       o lvmetad does not cache older metadata formats, e.g. lvm1, and will be
         temporarily disabled if they are seen.
       o To notify lvmetad about a device that is no longer present, the major
         and minor numbers must be given, not the path.
       Automatic activation
       When  event-driven  system  services detect a new LVM device, the first
       step is to automatically scan and cache the metadata from  the  device.
       This  is  done  by  pvscan  --cache.  A second step is to automatically
       activate LVs that are present on the new device.  This  auto-activation
       is  done  by the same pvscan --cache command when the option --activate
       ay is included.
       Auto-activation of VGs or LVs can be enabled/disabled using:
       lvm.conf(5) activation/auto_activation_volume_list
       For more information, see:
       lvmconfig --withcomments activation/auto_activation_volume_list
       When this setting is undefined, all LVs are auto-activated (when lvm is
       fully integrated with the event-driven system services.)
       When  a  VG  or  LV is not auto-activated, traditional activation using
       vgchange or lvchange --activate is needed.
       o pvscan auto-activation can be only done in combination with --cache.
       o Auto-activation is designated by the "a" argument in  --activate  ay.
         This  is meant to distinguish system generated commands from explicit
         user commands, although it can be used  in  any  activation  command.
         Whenever it is used, the auto_activation_volume_list is applied.
       o Auto-activation is not yet supported for LVs that are part of partial
         or clustered volume groups.
USAGE
       Display PV information.
       pvscan
           [ -e|--exported ]
           [ -n|--novolumegroup ]
           [ -s|--short ]
           [ -u|--uuid ]
           [ COMMON_OPTIONS ]
       Populate the lvmetad cache by scanning PVs.
       pvscan --cache
           [ -b|--background ]
           [ -a|--activate ay ]
           [ -j|--major Number ]
           [    --minor Number ]
           [ COMMON_OPTIONS ]
           [ String|PV ... ]
       Common options for command:
           [    --ignorelockingfailure ]
           [    --reportformat basic|json ]
       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 ]
           [    --profile String ]
           [    --version ]
OPTIONS
       -a|--activate y|n|ay
              Auto-activate LVs in a VG when the PVs scanned have completed
              the VG.  (Only ay is applicable.)
       -b|--background
              If the operation requires polling, this option causes the com-
              mand to return before the operation is complete, and polling is
              done in the background.
       --cache
              Scan one or more devices and send the metadata to lvmetad.
       --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 set-
              tings.  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.
       -e|--exported
              Only show PVs belonging to exported VGs.
       -h|--help
              Display help text.
       --ignorelockingfailure
              Allows a command to continue with read-only metadata operations
              after locking failures.
       --lockopt String
              Used to pass options for special cases to lvmlockd.  See lvm-
              lockd(8) for more information.
       --longhelp
              Display long help text.
       -j|--major Number
              The major number of a device.
       --minor Number
              The minor number of a device.
       -n|--novolumegroup
              Only show PVs not belonging to any VG.
       --profile String
              An alias for --commandprofile or --metadataprofile, depending on
              the command.
       -q|--quiet ...
              Suppress output and log messages. Overrides --debug and --ver-
              bose.  Repeat once to also suppress any prompts with answer
              'no'.
       --reportformat basic|json
              Overrides current output format for reports which is defined
              globally by the report/output_format setting in lvm.conf.  basic
              is the original format with columns and rows.  If there is more
              than one report per command, each report is prefixed with the
              report name for identification. json produces report output in
              JSON format. See lvmreport(7) for more information.
       -s|--short
              Short listing format.
       -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.
       -u|--uuid
              Show UUIDs in addition to device names.
       -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 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:  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.
SEE ALSO
       lvm(8) lvm.conf(5) lvmconfig(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) vgcon-
       vert(8)  vgdisplay(8)  vgexport(8)  vgextend(8)  vgimport(8)  vgimport-
       clone(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)  lvre-
       duce(8) lvremove(8) lvrename(8) lvresize(8) lvs(8) lvscan(8)
       lvm-fullreport(8) lvm-lvpoll(8) lvm2-activation-generator(8) blkdeacti-
       vate(8) lvmdump(8)
       dmeventd(8) lvmetad(8) lvmpolld(8) lvmlockd(8)  lvmlockctl(8)  clvmd(8)
       cmirrord(8) lvmdbusd(8)
       lvmsystemid(7) lvmreport(7) lvmraid(7) lvmthin(7) lvmcache(7)

Red Hat, Inc.      LVM TOOLS 2.02.187(2)-RHEL7 (2020-03-24)          PVSCAN(8)