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Backups

Summary

/home - Daily tape backup plus snapshots. 2 year retention period. 6 monthly offsite backup.

/work - Disk to disk backup, plus snapshots. 3 month retention period. 6 monthly offsite backup.

/data - No backups. No retention.

/data2 - No backups. No retention.

Tape backup

Home directories are backed up to tape weekly, with incremental backups done every night to capture changes during the previous 24 hours. Tapes are stored for 2 years.

Note - Every six months we conduct a full backup of your home and work directory files and they are taken to an offsite storage facility.

Snapshots

Snapshots sets aside a certain portion of the filesystem to capture images of the /home and /work filesystems at regular intervals in time. Whilst not a true backup, they are very useful since you can recover your own deleted files. Each snapshot image acts as a full backup at that instant in time.

Snapshots are conducted hourly, daily and weekly. On both /home and work we retain one days worth of hourly snapshots, two weeks worth of daily snapshots, and 3 months worth of weekly snapshots.

Snapshots are located throughout the filesystem in a directory called .snapshot. Use the cp command to recover a file from snapshots. e.g. To recover a file called somefile from the 3pm hourly snapshot use

  cp /home/user/.snapshot/hourly.15/somefile /home/user/
  

Note - The location of the snapshots for /home is the local filesystem. This is only partially the case for /work. To retrieve a snapshot from your work directory beyond one week old, please see the computing staff as these snapshots are located on a separate fileserver.

Disk to Disk backup

A full backup of your work directory exists on another fileserver on campus. This full backup is augmented by snapshot incremental backups such that the snapshot retention policy above is adhered to. The most recent 2 hourly snapshots as well as all snapshots older than one week are stored on the secondary fileserver. Thus in the event of a disaster we can recover /work to within one or two hours.