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

326 Administering volume snapshots
Creating instant snapshots
Note: This command is similar in usage to the vxassist snapstart command, and
supports the traditional third-mirror break-off snapshot model. As such, it does not
provide an instant snapshot capability.
Once you have added one or more snapshot mirrors to a volume, you can use the
vxsnap
make command with either the nmirror attribute or the plex attribute to create the
snapshot volumes.
Removing a snapshot mirror
To remove a single snapshot mirror from a volume, use this command:
# vxsnap [-g diskgroup] rmmir volume|volume_set
For example, the following command removes a snapshot mirror from the volume, vol1:
# vxsnap -g mydg rmmir vol1
Note: This command is similar in usage to the vxassist snapabort command.
If a volume set name is specified instead of a volume, a mirror is removed from each
volume in the volume set.
Removing a linked break-off snapshot volume
To remove a linked break-off snapshot volume from a volume, use this command:
# vxsnap [-g diskgroup] rmmir volume|volume_set mirvol=snapvol \
[mirdg=snapdiskgroup]
The mirvol and optional mirdg attributes specify the snapshot volume, snapvol, and its
disk group, snapdiskgroup. For example, the following command removes a linked
snapshot volume, prepsnap, from the volume, vol1:
# vxsnap -g mydg rmmir vol1 mirvol=prepsnap mirdg=mysnapdg
Adding a snapshot to a cascaded snapshot hierarchy
To create a snapshot and push it onto a snapshot hierarchy between the original volume
and an existing snapshot volume, specify the name of the existing snapshot volume as the
value of the infrontof attribute to the
vxsnap make command. The following example
shows how to place the space-optimized snapshot, thurs_bu, of the volume, dbvol, in
front of the earlier snapshot, wed_bu:
# vxsnap -g dbdg make source=dbvol/newvol=thurs_bu/\
infrontof=wed_bu/cache=dbdgcache
Similarly, the next snapshot that is taken, fri_bu, is placed in front of thurs_bu:
# vxsnap -g dbdg make source=dbvol/newvol=fri_bu/\
infrontof=thurs_bu/cache=dbdgcache