Snapshots

Snapshots are a implementation of copy on write that allows for a file system to quickly take a point in time copy of the file system and provide access to the data through a .snapshot directory.

We provide Snapshots on our ONStor, Nexenta and FluidFS filers to certain file systems.

Please see SnapshotFileSystems for a list of our file systems that have snapshots in the department.

Snapshot Policy

Our core file systems in the department are on a 4 hour snapshot cycle. Snapshots are taken at,

12am

4am

8am

12pm

4pm

8pm

We retain up to 8 hourly snapshots, 2 daily snapshots and 1 weekly snapshot.

The OpenLAB filesystems on which snapshots are available are listed on the SnapshotFileSystems page.

Snapshot Restoring

If you have deleted a file by mistake and you need to get it back, you can use the snapshots directory to recopy the file. This directory can typically be found in your home directory; it will be prepended by a ., so you will need to use the command "ls -a" to find it. It will be one of three:

• .snapshot for the ONStor (will be removed soon!) / NetApp filers
• .snapshots for the FluidFS filer
• .zfs/snapshots for the Nexenta / ZFS filers

The inside of one of these will look something like:

For an example of file restoration, please see this page.