Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

276 Administering volumes
Resizing a volume
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.
Resizing volumes using vxresize
Use the vxresize command to resize a volume containing a file system. Although other
commands can be used to resize volumes containing file systems, the
vxresize
command offers the advantage of automatically resizing certain types of file system as
well as the volume.
See the following table for details of what operations are permitted and whether the file
system must first be unmounted to resize the file system:
For example, the following command resizes the 1-gigabyte volume, homevol, in the
disk group, mydg, that contains a VxFS file system to 10 gigabytes using the spare disks
mydg10 and mydg11:
# vxresize -g mydg -b -F vxfs -t homevolresize homevol 10g \
mydg10 mydg11
The -b option specifies that this operation runs in the background. Its progress can be
monitored by specifying the task tag homevolresize to the
vxtask command.
Note the following restrictions for using
vxresize:
■ vxresize works with VxFS, JFS (derived from VxFS) and HFS file systems only.
■ In some situations, when resizing large volumes, vxresize may take a long time to
complete.
■ Resizing a volume with a usage type other than FSGEN or RAID5 can result in loss
of data. If such an operation is required, use the -f option to forcibly resize such a
volume.
■ You cannot resize a volume that contains plexes with different layout types.
Attempting to do so results in the following error message:
Table 8-1 Permitted resizing operations on file systems
Online JFS (Full-
VxFS)
Base JFS (Lite-
VxFS)
HFS
Mounted File System
Grow and shrink Not allowed Not allowed
Unmounted File System
Grow only Grow only Grow only