VERITAS Volume Manager 4.1 Administrator's Guide

Administering Volumes
Resizing a Volume
Chapter 8288
Resizing a Volume
Resizing a volume changes the volume size. For example, you might need
to increase the length of a volume if it is no longer large enough for the
amount of data to be stored on it. To resize a volume, use one of the
commands: vxresize (preferred), vxassist, or vxvol. Alternatively, you can
use the graphical VERITAS Enterprise Administrator (VEA) to resize
volumes.
If a volume is increased in size, the vxassist command automatically
locates available disk space. The vxresize command requires that you
specify the names of the disks to be used to increase the size of a volume.
The vxvol command requires that you have previously ensured that
there is sufficient space available in the plexes of the volume to increase
its size. The vxassist and vxresize commands automatically free unused
space for use by the disk group. For the vxvol command, you must do this
yourself. To find out by how much you can grow a volume, use the
following command:
# vxassist maxgrow volume
When you resize a volume, you can specify the length of a new volume in
sectors, kilobytes, megabytes, or gigabytes. The unit of measure is added
as a suffix to the length (s, m, k, or g). If no unit is specified, sectors are
assumed. The vxassist command also allows you to specify an increment
by which to change the volume’s size.
CAUTION If you use vxassist or vxvol to resize a volume, do not shrink it below the
size of the file system which is located on it. If you do not shrink the file
system first, you risk unrecoverable data loss. If you have a VxFS file
system, shrink the file system first, and then shrink the volume. Other
file systems may require you to back up your data so that you can later
recreate the file system and restore its data.