Storage Foundation Cluster File System High Availability 7.2 Administrator's Guide - Solaris

Creating multiple instant snapshots

You can create multiple instant snapshots for all volumes that form a consistent group. 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, from specified storage, 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 snapshot volumes (snapvol1, snapvol2 and so on) must have been prepared in advance.

The specified source volumes (vol1, vol2 and so on) may be the same volume or they can be different volumes.

If all the snapshots are to be space-optimized and to share the same cache, the following form of the command can be used:

# vxsnap [-g diskgroup] make \
  source=vol1/newvol=snapvol1/cache=cacheobj \
  source=vol2/newvol=snapvol2/cache=cacheobj \
  source=vol3/newvol=snapvol3/cache=cacheobj \
  [alloc=storage_attributes]

The vxsnap make command also allows the snapshots to be of different types, have different redundancy, and be configured from different storage, as shown here:

# vxsnap [-g diskgroup] make source=vol1/snapvol=snapvol1 \
  source=vol2[/newvol=snapvol2]/cache=cacheobj\
[/alloc=storage_attributes2][/nmirror=number2]
  source=vol3[/newvol=snapvol3][/alloc=storage_attributes3]\
/nmirror=number3

In this example, snapvol1 is a full-sized snapshot that uses a prepared volume, snapvol2 is a space-optimized snapshot that uses a prepared cache, and snapvol3 is a break-off full-sized snapshot that is formed from plexes of the original volume.

An example of where you might want to create mixed types of snapshots at the same time is when taking snapshots of volumes containing database redo logs and database tables:

# vxsnap -g mydg make \
  source=logv1/newvol=snplogv1/drl=sequential/nmirror=1 \
  source=logv2/newvol=snplogv2/drl=sequential/nmirror=1 \
  source=datav1/newvol=snpdatav1/cache=mydgcobj/drl=on \
  source=datav2/newvol=snpdatav2/cache=mydgcobj/drl=on

In this example, sequential DRL is enabled for the snapshots of the redo log volumes, and normal DRL is applied to the snapshots of the volumes that contain the database tables. The two space-optimized snapshots are configured to share the same cache object in the disk group. Also note that break-off snapshots are used for the redo logs as such volumes are write intensive.