lvreduce(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | USAGE | OPTIONS | VARIABLES | ENVIRONMENT VARIABLES | EXAMPLES | SEE ALSO | COLOPHON

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

NAME         top

       lvreduce - Reduce the size of a logical volume

SYNOPSIS         top

       lvreduce option_args position_args
           [ option_args ]

DESCRIPTION         top

       lvreduce reduces the size of an LV. The freed logical extents are
       returned to the VG to be used by other LVs. A copy-on-write
       snapshot LV can also be reduced if less space is needed to hold
       COW blocks. Use lvconvert(8) to change the number of data images
       in a RAID or mirrored LV.

       Be careful when reducing an LV's size, because data in the
       reduced area is lost. Ensure that any file system on the LV is
       resized before running lvreduce so that the removed extents are
       not in use by the file system.

       Sizes will be rounded if necessary. For example, the LV size must
       be an exact number of extents, and the size of a striped segment
       must be a multiple of the number of stripes.

       In the usage section below, --size Size can be replaced with
       --extents Number.  See both descriptions the options section.

USAGE         top

       lvreduce -L|--size [-]Size[m|UNIT] LV
           [ -l|--extents [-]Number[PERCENT] ]
           [ -A|--autobackup y|n ]
           [ -f|--force ]
           [ -n|--nofsck ]
           [ -r|--resizefs ]
           [    --noudevsync ]
           [    --reportformat basic|json ]
           [ COMMON_OPTIONS ]

       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         top

       -A|--autobackup y|n
              Specifies if metadata should be backed up automatically
              after a change.  Enabling this is strongly advised! See
              vgcfgbackup(8) for more information.

       --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.

       -l|--extents [-]Number[PERCENT]
              Specifies the new size of the LV in logical extents.  The
              --size and --extents options are alternate methods of
              specifying size.  The total number of physical extents
              used will be greater when redundant data is needed for
              RAID levels.  An alternate syntax allows the size to be
              determined indirectly as a percentage of the size of a
              related VG, LV, or set of PVs. The suffix %VG denotes the
              total size of the VG, the suffix %FREE the remaining free
              space in the VG, and the suffix %PVS the free space in the
              specified PVs.  For a snapshot, the size can be expressed
              as a percentage of the total size of the origin LV with
              the suffix %ORIGIN (100%ORIGIN provides space for the
              whole origin).  When expressed as a percentage, the size
              defines an upper limit for the number of logical extents
              in the new LV. The precise number of logical extents in
              the new LV is not determined until the command has
              completed.  When the plus + or minus - prefix is used, the
              value is not an absolute size, but is relative and added
              or subtracted from the current size.

       -f|--force ...
              Override various checks, confirmations and protections.
              Use with extreme caution.

       -h|--help
              Display help text.

       --lockopt String
              Used to pass options for special cases to lvmlockd.  See
              lvmlockd(8) for more information.

       --longhelp
              Display long help text.

       -n|--nofsck
              Do not perform fsck before resizing filesystem when
              filesystem requires it. You may need to use --force to
              proceed with this option.

       --nolocking
              Disable locking.

       --noudevsync
              Disables udev synchronisation. The process will not wait
              for notification from udev. It will continue irrespective
              of any possible udev processing in the background. Only
              use this if udev is not running or has rules that ignore
              the devices LVM creates.

       --profile String
              An alias for --commandprofile or --metadataprofile,
              depending on the command.

       -q|--quiet ...
              Suppress output and log messages. Overrides --debug and
              --verbose.  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.

       -r|--resizefs
              Resize underlying filesystem together with the LV using
              fsadm(8).

       -L|--size [-]Size[m|UNIT]
              Specifies the new size of the LV.  The --size and
              --extents options are alternate methods of specifying
              size.  The total number of physical extents used will be
              greater when redundant data is needed for RAID levels.
              When the plus + or minus - prefix is used, the value is
              not an absolute size, but is relative and added or
              subtracted from the current size.

       -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         top

       LV
              Logical Volume name.  See lvm(8) for valid names.  An LV
              positional arg generally includes the VG name and LV name,
              e.g. VG/LV.

       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         top

       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         top

       Reduce the size of an LV by 3 logical extents:
       lvreduce -l -3 vg00/lvol1

SEE ALSO         top

       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)
       vgconvert(8) vgdisplay(8) vgexport(8) vgextend(8) vgimport(8)
       vgimportclone(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) lvm2-activation-generator(8)
       blkdeactivate(8) lvmdump(8)

       dmeventd(8) lvmpolld(8) lvmlockd(8) lvmlockctl(8) cmirrord(8)
       lvmdbusd(8)

       lvmsystemid(7) lvmreport(7) lvmraid(7) lvmthin(7) lvmcache(7)

COLOPHON         top

       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 tarball
       https://github.com/lvmteam/lvm2/archive/v2_03_10.tar.gz fetched
       from ⟨https://github.com/lvmteam/lvm2/releases⟩ on 2020-12-18.
       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 2.03.10(2) (2020-08-09)        LVREDUCE(8)

Pages that refer to this page: lvmvdo(7)lvchange(8)lvconvert(8)lvcreate(8)lvdisplay(8)lvextend(8)lvm(8)lvmconfig(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)vgmerge(8)vgmknodes(8)vgreduce(8)vgremove(8)vgrename(8)vgs(8)vgscan(8)vgsplit(8)