1. Technology
Linux / Unix Command: lvreduce
Command Library

NAME

lvreduce - reduce the size of a logical volume  

SYNOPSIS

lvreduce [-A|--autobackup {y|n}] [-d|--debug] [-f|--force] [-h|--help] {-l|--extents [-]LogicalExtentsNumber| -L|--size [-]LogicalVolumeSize[kKmMgGtT]} [-v|--verbose] LogicalVolumePath  

DESCRIPTION

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 the (eg) filesystem on the volume is resized running lvreduce so that the extents that are to be removed are not in use. If the filesystem is ext2 then you can use the e2fsadm(8) command to both resize the filesystem and the logical volume together.
Shrinking snapshot logical volumes (see lvcreate(8) for information to create snapshots) is supported as well.  

OPTIONS

-A, --autobackup y/n
Controls automatic backup of VG metadata after the change ( see vgcfgbackup(8) ). Default is yes.
-d, --debug
Enables additional debugging output (if compiled with DEBUG).
-f, --force
Force size reduction without any question.
-h, --help
Print a usage message on standard output and exit successfully.
-l, --extents [-]LogicalExtentsNumber
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 will be taken as an absolute size.
-L, --size [-]LogicalVolumeSize[kKmMgGtT]
Reduce or set the logical volume size in units of megabyte by default. A size suffix of k for kilobyte, m for megabyte, g for gigabyte or t for terabyte is optional. With the - sign the value will be subtracted from the logical volume's actual size and without it the will be taken as an absolute size.
-v, --verbose
Gives verbose runtime information about lvreduce's activities.
 

Example

"lvreduce -l -3 /dev/vg00/lvol1" reduces the size of logical volume lvol1 in volume group vg00 by 3 logical extents.  

Important: Use the man command (% man) to see how a command is used on your particular computer.

>> Linux/Unix Command Library

>> Shell Command Library

You can opt-out at any time. Please refer to our privacy policy for contact information.

Discuss in my forum

©2014 About.com. All rights reserved.