Amanda and Grandfather-Father-Son (GFS) backup tape rotation

The GFS tape rotation scheme is a popular method of maintaining backups on a daily, weekly, and monthly basis. The primary purpose of the GFS scheme is to suggest a minimum standard and consistent interval at which to rotate and retire the media.

In general, GFS backup schemes are based on a seven-day weekly schedule beginning any day. A full backup is performed at least once a week. On all other days, full, partial, or no backups are performed. The daily backups are the Sons. One full backup in the week (the weekly backup) is the Father. One full backup of the month (the monthly backup) is the Grandfather. GFS rotation schemes allow you to back up your servers for an entire year using a minimum number of media.

Amanda can be used to implement GFS tape rotation schedule. User can implement three backup sets for daily, weekly, monthly schedule. An example for 5 day GFS tape rotation is explained below.

Daily full/incremental backup on Mon-Thu, weekly full backup on Fridays and monthly full backup on first Friday of the month.

  1. Daily backup set is scheduled to run weekdays (M-Thu). The Amanda strategy is set to “inconly” and a tape rotation cycle of 4.
  2. Weekly backup set is scheduled to do backup on all Fridays except first one in the month. The Amanda strategy is set to “noinc” and a tape rotation cycle of 5.
  3. Monthly backup set is scheduled to to backup on first Friday of the month. The Amanda strategy is set to “noinc” and a tape rotation cycle of 13.

Amanda enterprise management console allows the administrator to identify the media volume that was used for the backup, media volume that will be used next and also information about client, media backup failures.

Users can move tapes from daily backup set to weekly backup set and from weekly backup set to monthly backup set to reduce the wear/tear on the media.

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