Provided by: lvm2_2.03.02-2ubuntu6_amd64 bug

NAME

       lvreduce - Reduce the size of a logical volume

SYNOPSIS

       lvreduce option_args position_args
           [ option_args ]

DESCRIPTION

       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

       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

       -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

       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

       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

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

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)  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)