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 ]
           [    --longhelp ]
           [    --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.

       --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.

       --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) lvmetad(8) lvmpolld(8) lvmlockd(8) lvmlockctl(8) clvmd(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, send it to linux-lvm@redhat.com.  This page was obtained
       from the project's upstream Git repository 
       ⟨git://sourceware.org/git/lvm2.git⟩ on 2017-09-15.  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 2.02.175(2)-git (2017-09-13)        LVREDUCE(8)

Pages that refer to this page: 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)