pvscan - List all physical volumes
pvscan scans all supported LVM block devices in the system for PVs.
Scanning with lvmetad
pvscan operates differently when used with the lvmetad
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 historical
reasons. To avoid disrupting the system with extraneous disk scanning, an
ordinary pvscan (without --cache) will simply read metadata from lvmetad like
other LVM commands. It does not do anything beyond displaying the current
state of the cache.
- When given specific device name arguments, pvscan --cache
will only read the named devices.
- LVM udev rules and systemd services are used to initiate
automatic device scanning.
- 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
lvmconfig --withcomments devices/global_filter
- 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.
- lvmetad does not cache older metadata formats, e.g. lvm1,
and will be temporarily disabled if they are seen.
- To notify lvmetad about a device that is no longer present,
the major and minor numbers must be given, not the path.
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:
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.
- pvscan auto-activation can be only done in combination with
- 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
- Auto-activation is not yet supported for LVs that are part
of partial or clustered volume groups.
Display PV information.
[ COMMON_OPTIONS ]
Populate the lvmetad cache by scanning PVs.
[ --minor Number
[ COMMON_OPTIONS ]
[ String|PV ... ]
Common options for command:
[ --reportformat basic
Common options for lvm:
[ --commandprofile String
[ --config String
[ --driverloaded y
[ --profile String
Auto-activate LVs in a VG when the PVs scanned have completed the VG. (Only
If the operation requires polling, this option causes the command to return
before the operation is complete, and polling is done in the background.
Scan one or more devices and send the metadata to lvmetad.
The command profile to use for command configuration. See lvm.conf
more information about profiles.
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
(5) for more information about config.
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).
If set to no, the command will not attempt to use device-mapper. For testing and
Only show PVs belonging to exported VGs.
Display help text.
Allows a command to continue with read-only metadata operations after locking
Display long help text.
The major number of a device.
The minor number of a device.
Only show PVs not belonging to any VG.
An alias for --commandprofile or --metadataprofile, depending on the
Suppress output and log messages. Overrides --debug and --verbose. Repeat once
to also suppress any prompts with answer 'no'.
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
Short listing format.
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
Show UUIDs in addition to device names.
Set verbose level. Repeat from 1 to 4 times to increase the detail of messages
sent to stdout and stderr.
Display version information.
Do not prompt for confirmation interactively but always assume the answer yes.
Use with extreme caution. (For automatic no, see -qq.)
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):
]... Start and length range
(counting from 0): PV
See the option description for information about the string content.
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.)
(8) for information about environment variables used by lvm. For
example, LVM_VG_NAME can generally be substituted for a required VG parameter.