For example, when you have a virtual device which was created then the snapshot was taken you can use
ufsdump to backup the file system.
In the pre
fssnap days, you had to bring the system into single-user mode and then use
ufsdump, alternately, break the file system mirror, backup the mirror then reattach the mirror once the backup has completed.
- Check if any snapshot exists and it's current state (if no output then no snapshots exist.):
# fssnap -i
- Take a snapshot of the / (root) file system:
# fssnap -o bs=/share/snapshots / /dev/fssmap/0From the above output we see the backing-store is
- We can perform a backup of the snapshot, for example:
# ufsdump -0fu /dev/rmt/0n /dev/fssnap/0
- Now we can remove the snapshot:
# fssnap -d /dev/fssnap/0 Delete snapshot 0.
If you attempt to create any additional snapshots for the same UFS file system, you receive the following error:
# fssnap -o /share/snapshots / fssnap: Fatal: /share/snapshots/0 already exists.
In this case. you will need to remove the old snapshot in order to create a new one.
Additionally, you can get information on a snapshot using the
fssnap -i command, for example:
# fssnap -i Snapshot number : 0 Block Device : /dev/fssnap/0 Raw Device : /dev/rfssnap/0 Mount point : / Device state : idle Backing store path : /share/snapshots/0 Backing store size : 0 KB Maximum backing store size : Unlimited Snapshot create time : Thu Nov 19 16:49:08 2009 Copy-on-write granularity : 32 KB