Ubuntu Manpages

lvreduce

reduce the size of a logical volume

lvreduce [-A|--autobackup {y|n}] [-d|--debug] [-h|--help] [-t|--test] [-v|--verbose] [--version] [-f|--force] [--noudevsync] {-l|--extents [-]LogicalExtentsNumber[%{VG|LV|FREE|ORIGIN}] | [-L|--size [-]LogicalVolumeSize[bBsSkKmMgGtTpPeE]} [-n|--nofsck] [-r|--resizefs] LogicalVolume{Name|Path}

lvreduce allows you to reduce the size of a logical volume. Be careful when reducing a logical volume's size, because data in the reduced part is lost!!!
You should therefore ensure that any filesystem on the volume is resized before running lvreduce so that the extents that are to be removed are not in use.
Shrinking snapshot logical volumes (see lvcreate(8) for information to create snapshots) is supported as well. But to change the number of copies in a mirrored logical volume use lvconvert(8).
Sizes will be rounded if necessary - for example, the volume size must be an exact number of extents and the size of a striped segment must be a multiple of the number of stripes.

See lvm(8) for common options.

Force size reduction without prompting even when it may cause data loss.
Reduce or set the logical volume size in units of logical extents. With the - sign the value will be subtracted from the logical volume's actual size and without it the value will be taken as an absolute size. The number can also be expressed as a percentage of the total space in the Volume Group with the suffix %VG, relative to the existing size of the Logical Volume with the suffix %LV, as a percentage of the remaining free space in the Volume Group with the suffix %FREE, or (for a snapshot) as a percentage of the total space in the Origin Logical Volume with the suffix %ORIGIN. The resulting value for the substraction is rounded downward, for the absolute size it is rounded upward.
Reduce or set the logical volume size in units of megabytes. A size suffix of k for kilobyte, m for megabyte, g for gigabytes, t for terabytes, p for petabytes or e for exabytes is optional. With the - sign the value will be subtracted from the logical volume's actual size and without it it will be taken as an absolute size.
Do not perform fsck before resizing filesystem when filesystem requires it. You may need to use --force to proceed with this option.
Disable udev synchronisation. The process will not wait for notification from udev. It will continue irrespective of any possible udev processing in the background. You should only use this if udev is not running or has rules that ignore the devices LVM2 creates.
Resize underlying filesystem together with the logical volume using fsadm(8).

Reduce the size of logical volume lvol1 in volume group vg00 by 3 logical extents:

lvreduce -l -3 vg00/lvol1

fsadm(8), lvchange(8), lvconvert(8), lvcreate(8), lvextend(8), lvm(8), lvresize(8), vgreduce(8)