Today’s world requires defensive data protection strategies as well as reliable and repeatable recovery procedures. The ZFS Storage Appliance has integrated read-only snapshots that can be scheduled and replicated to other locations. Snapshots can be scheduled down to every 5 minutes, daily, weekly, or monthly. Snapshots can be compressed, encrypted, scheduled and replicated to another ZFS Storage Appliance in an isolated environment or even replicated to the cloud. Snapshots can be rolled back to a point in time to recover from an accidental or malicious operation. Leveraging ZFS snapshots provides another layer of data protection and recovery.

I remember working on a tight deadline and my data files were accidentally truncated. I went straight to freak out mode. I couldn’t fathom how I was going to recover.

Ruby Slippers

I was reminded that my home directory was on a ZFS Storage Appliance and daily snapshots were running to provide point in time versions of our home directories. I had the ruby slippers! Recovery was as simple as cd’ing into my most recent ZFS snapshot directory and copying out the required files. Resolved in a matter of minutes. Deadline met.


Snapshots are also running on our build servers so that developers can rollback or clone to create a new build to test a bug fix, if needed. Very convenient for dev and test environments.


You can identify the latest file system snapshots and then roll them back from the ZFS Storage Appliance to recover from a ransomware attack.

We’re Not in Kansas Any More

Fast-forward to present day: Cybersecurity is on everyone’s mind. Oracle customers have recovered from ransomware attacks by rolling back their ZFS snapshots. Google describes other cases where people have recovered with ZFS snapshots or other vendors are offering ZFS snapshots for recovery. Many ZFS Storage Appliance customers rely on scheduled snapshots and replication in addition to their backup and DR strategies. Snapshots are another checkbox in your cyber protection/recovery runbook.


A common and related priority for today’s customers is meeting data governance, regularly compliance, or legal hold use cases with retention policies.


In the latest OS8.8.39 micro release, ZFS snapshot retention is now available. Snapshot retention can be enabled for both manual and scheduled (automatic) snapshots to meet your compliance requirements. Combining snapshot retention with the separation of powers or authorizations to delegate who can apply snapshot retention and who can release retention means that data will be even harder to compromise.

ZFS snapshots are very space efficient because they share blocks with the file system so they only increase in size when the file system data changes. You can further optimize space by enabling LZ4 compression.
Here’s a brief summary of the snapshot retention features:

  • Manual snapshot retention allows you to retain a snapshot for an open-end period and then you can remove the retention when it is no longer required.
  • Scheduled (automatic) snapshot retention includes both KEEP-AT-MOST and RETENTION settings so that you can keep a number of scheduled snapshots and then also retain/lock an equivalent number or subset of those scheduled snapshots.

For more information about adding snapshot retention to your business environment, see Oracle ZFS Storage: Best Practices for Implementing Snapshot Retention.


If you must prepare for the possibility of a spell being cast over your data, consider that you have these features at the click of your heels.