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

354 Creating and administering volume sets
Creating a volume set
■ Volume sets can be used in place of volumes with the following vxsnap operations
on instant snapshots:
addmir, dis, make, prepare, reattach, refresh, restore,
rmmir, split, syncpause, syncresume, syncstart, syncstop, syncwait, and
unprepare. The third-mirror break-off usage model for full-sized instant snapshots
is supported for volume sets provided that sufficient plexes exist for each volume in
the volume set. See “Administering volume snapshots” on page 295 and “Creating
instant snapshots of volume sets” on page 326 for more information.
■ A full-sized snapshot of a volume set must itself be a volume set with the same
number of volumes and the same volume index numbers as the parent. The
corresponding volumes in the parent and snapshot volume sets are also subject to the
same restrictions as apply between standalone volumes and their snapshots.
Creating a volume set
To create a volume set for use by Veritas File System (VxFS), use the following
command:
# vxvset [-g diskgroup] -t vxfs make volset volume
Here volset is the name of the volume set, and volume is the name of the first volume in
the volume set. The
-t option defines the content handler subdirectory for the application
that is to be used with the volume. This subdirectory contains utilities that an application
uses to operate on the volume set. As the operation of these utilities is determined by the
requirements of the application and not by VxVM, it is not discussed further here.
For example, to create a volume set named myvset that contains the volume vol1, in
the disk group mydg, you would use the following command:
# vxvset -g mydg -t vxfs make myvset vol1
Adding a volume to a volume set
Having created a volume set containing a single volume, you can use the following
command to add further volumes to the volume set:
# vxvset [-g diskgroup] [-f] addvol volset volume
For example, to add the volume vol2, to the volume set myvset, use the following
command:
# vxvset -g mydg addvol myvset vol2
Caution: The -f (force) option must be specified if the volume being added, or any
volume in the volume set, is either a snapshot or the parent of a snapshot. Using this option
can potentially cause inconsistencies in a snapshot hierarchy if any of the volumes
involved in the operation is already in a snapshot chain.