LVREDUCE(8) System Manager's Manual LVREDUCE(8)
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 re-
turned 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 lv-
convert(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) set-
tings. The String arg uses the same format as lvm.conf(5), or
may use section/field syntax. See lvm.conf(5) for more informa-
tion 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 com-
mand. 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) com-
mand. This overrides the lvm.conf(5) devices/devicesfile and de-
vices/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 de-
notes 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 com-
mand 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 sys-
tem.
--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 lvm-
lockd(8) for more information.
--longhelp
Display long help text.
-n|--nofsck
Do not perform fsck when resizing the file system with --re-
sizefs.
--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 pro-
duce incorrect results.
--noudevsync
Disables udev synchronization. The process will not wait for no-
tification from udev. It will continue irrespective of any possi-
ble 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 --ver-
bose. 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). ba-
sic 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 op-
tions 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 im-
plemented by disabling all metadata writing but nevertheless re-
turning 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 de-
tail 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 posi-
tional arg generally includes the VG name and LV name, e.g.
VG/LV.
String See the option description for information about the string con-
tent.
Size[UNIT]
Size is an input number that accepts an optional unit. Input
units are always treated as base two values, regardless of capi-
talization, e.g. 'k' and 'K' both refer to 1024. The default in-
put unit is specified by letter, followed by |UNIT. UNIT repre-
sents 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 pa-
rameter.
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)
Red Hat, Inc. LVM TOOLS 2.03.31(2) (2025-02-27) LVREDUCE(8)
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