ZFS Snapshots Demo (5 Minutes)

Description

This demo is a continuation of the ZFS Pooled Storage Demo, however, it could easily be adapted to work with any storage pool. We essentially create a snapshot of our existing file system, change it's state and restore the snapshot.

OpenSolaris Versions Supported

2008.05, 2008.11

Points to Hit

ZFS Snapshots are quick and efficient.

Demo Prep

You need a storage pool

Gotchas

None yet known

Demo

Show the existing file systems and snapshots in the file system zfs list -t all | grep stripedpool
Take a snapshot of your existing file system zfs snapshot stripedpool@today
Show the new snapshot in the file system zfs list -t all | grep stripedpool. Notice it's not consuming any space, however, it does refer to the amount of space used by the file in the file system.
Delete the file(s) in the file system.
Copy or create a new file in the file system.
Run zfs list -t all | grep stripedpool again. The amount of space referred to by the file system itself should change, but the snapshot still refers to the size of the file(s) deleted.
Switch to the /stripedpool/.zfs/snapshot/today directory to show the data is still accessible.
Switch back to /stripedpool and restore the file system zfs rollback -r stripedpool@today
Notice everything is back how it was when the snapshot was created. Also notice the new file is gone.
Run zfs list -t all | grep stripedpool. Notice the file system is now using the same amount to which the snapshot is referring.

Demo Cleanup

If your moving on to the ZFS Clones Demo, do nothing, otherwise:
- cd /
- zpool destroy stripedpool

ZFSSnapshotsDemo