lvreduce(8) — Linux manual page
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
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 ]
[ --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
Devices that the command can use. 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.
-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 before resizing filesystem when
filesystem requires it. You may need to use --force to
proceed with this option.
--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.
--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(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. 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: 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)
COLOPHON
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 project's upstream Git repository
⟨git://sourceware.org/git/lvm2.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-11.) 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 2.03.25(2)-git (2024-05-16) LVREDUCE(8)
Pages that refer to this page: lvmvdo(7), lvchange(8), lvconvert(8), lvcreate(8), lvdisplay(8), lvextend(8), lvm(8), lvmconfig(8), lvmdevices(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), vgimportdevices(8), vgmerge(8), vgmknodes(8), vgreduce(8), vgremove(8), vgrename(8), vgs(8), vgscan(8), vgsplit(8)