VERITAS Storage Foundation 4.1 Intelligent Storage Provisioning Administrator's Guide

Creating Instant Snapshots
86 VERITAS Storage Foundation ISP Administrator’s Guide
Creating Multiple Instant Snapshots
Note In these examples, all snapshot volumes and any cache volumes must be prepared in
advance as described in “Creating a Volume for Use as a Full-Sized Instant Snapshot” on
page 76 and “Creating a Shared Cache Volume and Preparing Space-Optimized Snapshots”
on page 77.
To make it easier to create snapshots of several volumes at the same time, the vxsnap make
command accepts multiple tuples that define the source and snapshot volumes names as their
arguments. For example, to create three instant snapshots, each with the same redundancy, the
following form of the command can be used:
# vxsnap [-g diskgroup] make \
source=vol1/snapvol=snapvol1 \
source=vol2/snapvol=snapvol2 \
source=vol3/snapvol=snapvol3
The specified source volumes (vol1, vol2 and so on) may be the same volume or different
volumes.
The vxsnap make command allows the snapshots to be of different types as shown here:
# vxsnap [-g diskgroup] make \
source=vol1/snapvol=snapvol1 \
source=vol2/snapvol=snapvol2
In this example, snapvol1 is a full-sized snapshot, and snapvol2 is a space-optimized
snapshot.
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/snapvol=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/snapvol=fri_bu/\
infrontof=thurs_bu/cache=dbdgcache
For more information on the application of cascaded snapshots, see the VERITAS Volume Manager
Administrator’s Guide.