plucky (8) lvreduce.8.gz

Provided by: lvm2_2.03.27-1ubuntu1_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|json_std ]
           [    --fs String ]
           [    --fsmode String ]
           [ COMMON_OPTIONS ]

       Common options for lvm:
           [ -d|--debug ]
           [ -h|--help ]
           [ -q|--quiet ]
           [ -t|--test ]
           [ -v|--verbose ]
           [ -y|--yes ]
           [    --commandprofile String ]
           [    --config String ]
           [    --devices PV ]
           [    --devicesfile String ]
           [    --driverloaded y|n ]
           [    --journal String ]
           [    --lockopt String ]
           [    --longhelp ]
           [    --nohints ]
           [    --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(5) settings.  The String arg uses the
              same format as lvm.conf(5), 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).

       --devices PV
              Restricts the devices that are visible and accessible to the command.   Devices  not  listed  will
              appear  to  be missing. This option can be repeated, or accepts a comma separated list of devices.
              This overrides the devices file.

       --devicesfile String
              A file listing devices that LVM should use.  The file  must  exist  in  /etc/lvm/devices/  and  is
              managed  with  the  lvmdevices(8) command.  This overrides the lvm.conf(5) devices/devicesfile and
              devices/use_devicesfile settings.

       --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.

       --fs String
              Control file system resizing when resizing an LV.  checksize: Check the fs size and reduce the  LV
              if  the  fs is not using the reduced space (fs reduce is not needed.) If the reduced space is used
              by the fs, then do not resize the fs or LV, and return an error.   (checksize  only  applies  when
              reducing,  and  does nothing for extend.)  resize: Resize the fs by calling the fs-specific resize
              command.  This may also include mounting, unmounting, or running fsck.  See  --fsmode  to  control
              mounting  behavior,  and  --nofsck  to  disable fsck.  resize_fsadm: Use the old method of calling
              fsadm to handle the  fs  (deprecated.)  Warning:  this  option  does  not  prevent  lvreduce  from
              destroying  file  systems  that are unmounted (or mounted if prompts are skipped.)  ignore: Resize
              the LV without checking for or handling a file system.  Warning: using ignore when reducing the LV
              size may destroy the file system.

       --fsmode String
              Control file system mounting behavior for fs resize.  manage: Mount or unmount the fs as needed to
              resize the fs, and attempt to restore the original mount state at the end.  nochange: Do not mount
              or  unmount the fs. If mounting or unmounting is required to resize the fs, then do not resize the
              fs or the LV and fail the command.  offline: Unmount the fs if it is mounted, and  resize  the  fs
              while  it is unmounted. If mounting is required to resize the fs, then do not resize the fs or the
              LV and fail the command.

       -h|--help
              Display help text.

       --journal String
              Record information in the systemd journal.  This information is in addition to information enabled
              by  the  lvm.conf  log/journal  setting.   command: record information about the command.  output:
              record the default command output.  debug: record full command debugging.

       --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 when resizing the file system with --resizefs.

       --nohints
              Do not use the hints file to locate devices for PVs. A command may read more devices to  find  PVs
              when  hints  are  not  used.  The command will still perform standard hint file invalidation where
              appropriate.

       --nolocking
              Disable locking. Use with caution, concurrent commands may produce incorrect results.

       --noudevsync
              Disables udev synchronization. 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|json_std
              Overrides  current output format for reports which is defined globally by the report/output_format
              setting in lvm.conf(5).  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. json_std produces report output in  JSON  format  which  is
              more compliant with JSON standard.  See lvmreport(7) for more information.

       -r|--resizefs
              Resize  the fs using the fs-specific resize command.  May include mounting, unmounting, or running
              fsck. See --fsmode to control mounting behavior, and --nofsck to disable fsck. See --fs  for  more
              options (--resizefs is equivalent to --fs resize.)

       -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:  b|B  is
              bytes,  s|S  is  sectors of 512 bytes, k|K is KiB, m|M is MiB, g|G is GiB, t|T is TiB, p|P is PiB,
              e|E is EiB.  (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), lvmdevices(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), vgimportdevices(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), blkdeactivate(8), lvmdump(8),

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

       lvmsystemid(7), lvmreport(7), lvmcache(7), lvmraid(7), lvmthin(7), lvmvdo(7), lvmautoactivation(7)