Table of Contents

ZFS Snapshots

Oracle Documentation: https://docs.oracle.com/cd/E23824_01/html/821-1448/gavvx.html

Napp-IT Replication Docs: https://www.napp-it.org/extensions/replication.html

Napp-IT Documentation: https://napp-it.org/doc/downloads/napp-it.pdf

ZFS snapshots can be a fast and easy way to enhance your disaster preparedness.

:!: Napp-IT has a commercial (Pro) Replication module available that performs ZFS snapshots and pulls them to another ZFS server.

Recover Data from Snapshots

By File

Snapshots are automatically mounted (read only) under /$FILESYSTEM/.zfs/snapshot/$SNAPSHOTNAME. You can use the CLI to copy data you want to recover to another location.

Example with a (three level) nested ZFS filesystem showing an NFS storage repository containing VHDs: 

/toplevelfs/midlevelfs/bottomlevelfs/.zfs/snapshot/job-name-job-ID_year.month.day.hour.min.sec/nfs_sr_id/

Using Clones

:!: As with snapshots, creating a clone (writeable filesystem) is nearly instantaneous and initially consumes no additional disk space. Clones can only be created from snapshots.

If you don't want to muck with the .zfs hidden folder, you could also:

  1. Clone the snapshot
  2. Copy out your files/folders that need recovering
  3. Destroy the clone

Rollback

You can use the ZFS rollback feature to discard all changes made to a file system since a specific snapshot was created. The file system reverts to its state at the time the snapshot was taken.

If you roll back, all intermediate snapshots and all clones based on them are destroyed without an undo option.

For most rollback cases, using Windows and Previous Version is the suggested method for a roll back as you can restrict the rollback to files and folders.

You can use Napp-IT menu ZFS-Filesystem → Rollback to initiate a rollback.