File Server Snapshots

Some of the file servers used by the school support SnapShot technology. In essence this provides a "point in time" representation of the files on the file-server and can assist with retrieving files which may have inadvertantly been deleted or corrupted.

The snapshots should not be used in place of your own backups which you are reccomended to take on a regular basis.

In particular, the file-server storing home directories supports this technology.

Snapshots do not use up any of your filestore quota.

Snapshot timetable

The file-server automatically manages snapshots and takes them at periodic intervals on a rolling basis:

  • Four times a day at 8am, 12 noon, 4pm and 8pm. (hourly.0 is the most recent). The most recent 6 hourly snapshots are kept.
  • Nightly at midnight, daily.0 is midnight today and daily.1 is midnight yesterday.

So, for example if it is currently 2pm on Tuesday, the snapshots will be as follows:

  • hourly.0 - 12 noon Tuesday
  • hourly.1 - 8am Tuesday
  • hourly.2 - 8pm Monday
  • hourly.3 - 4pm Monday
  • hourly.4 - 12 noon Monday
  • hourly.5 - 8am Monday
  • nightly.0 - Midnight Tuesday
  • nightly.1 - Midnight Monday

Accessing Snapshots

Snapshots are presented to users of both Windows and Unix/Linux but in a different way.

Linux/Solaris

You can access a snapshot from Linux/Solairs by cd'ing to the directory .snapshot (this may not be visible from a ls command):

  • cd ~/<path>/.snapshot
  • cd ~/.snapshot

The snapshots are read-only, so to recover a file, you must copy it back into your file-space.

Windows

Under Windows, the snapshot directory is called ~snapshot, which may be a hidden file under Windows Explorer:

  • file:\\<path>/~snapshot

The snapshots are read-only, so to recover a file, you must copy it back into your file-space.

Under Windows, the snapshots are also provided as "previous versions". You can access this by right clicking on a directory and selecting properties. You can then select the "Previous Versions" tab:

Screenshot of Previous Version window You are then presented with a list of snapshots available for the directory and shown the time and date when the snapshot was taken, you can the use the "Restore" button to recover a whole directory, "Copy" to copy the snapshot to a new location, or "View" to view the contents of the snapshot - from there you could choose to copy back just a single file.

Important Note: When using the restore option, the directory will be returned to the state when the snapshot was taken - i.e. any new files created since the snapshot will be lost.