Amanda and Grandfather-Father-Son (GFS) Backup Tape Rotation

Amanda and Grandfather-father-son backup tape rotation

Grandfather-Father-Son (GFS) backup is one of the most popular backup schemes. It allows you to save data into the two different places with three repeating frequencies.

This post covers the GFS backup scheme and how you can implement it in your organization.


Every organization relies on its computer networks to store and retrieve vital data from databases. Backup tapes, cloud storage services, and external hard drives are the data backup services that companies use to protect their data.

It is better if you have a disaster recovery plan ready, as disasters occur unplanned. In case you don’t have one, then a virus breach or a catastrophic event can bring your business down. Smart companies are aware that they need a disaster recovery plan, so to prevent the damaging effects of data loss they will already have one handy.

Although cloud storage and robust backup solutions are becoming more cost-effective, there are still businesses that stick with offsite tape storage and rotation. Magnetic tape is an ideal storage medium for backing up individual workstations or small networks, as it can store high volumes of information at a low price. Also, during an event of theft, natural disaster or fire, tape backups allow companies to restore and recover lost data immediately.

Larger companies look for vendors who specialize in off-site storage, as they deal with confidential information and to ensure the information is secure.

The Importance of Tape Rotation

An efficient data recovery plan with offsite magnetic tape storage is incomplete without rotation. Companies need to rotate their tape cartridges to keep their backup data remains up-to-date.

There are several different strategies and rotations organizations use to ensure all data is adequately backed up and secure.  Let’s have a look at some insights on tape rotation strategies and how often you should rotate them.

Backup Tape Storage Rotation Strategy

A company can access data without fail with a good rotation strategy. It protects the tape from excessive wear and tear, which can make retrieving data impossible. Tape rotation needs a regular schedule, often with added expenses that offer greater security against disaster.

Grandfather-Father-Son Tape Rotation Frequency

The frequency of tape rotation depends on the company relying on data storage and retrieval. Companies with high volumes of sensitive data require a sophisticated and secure rotation schedule. While small businesses need to implement something cost-effective and straightforward.

Most companies go for one of these three rotation schedules six-tape, Grandfather-Father-Son, and Tower of Hanoi scheme. Out of the three Grandfather-Father-Son is the most widely used scheme for tape backup rotation. It is a combination of security with ease of implementation.

GFS is simple as it runs on a traditional calendar. A full backup performed on the last day is  ‘grandfather’, and this tape is stored permanently offsite. A full backup done on the last day of every week is the ‘father’ and stored offsite. Then, an incremental backup done daily is the ‘son’. Son tapes can be stored onsite, or offsite depends on the volume of data changes.

Adding up the tapes, you will have four son tapes (assuming a five day work week), three father tapes, and a new grandfather tape every month. Most companies look for permanent storage on a quarterly or yearly basis with the grandfather tapes.

The main purpose of the GFS tape rotation scheme is to suggest a minimum standard and consistent interval at which to rotate and retire the media. GFS rotation schemes allow you to back up your servers for an entire year using a minimum number of media.

Amanda & Grandfather, Father and Son Backup

Amanda can be used to implement the GFS tape rotation schedule. Users can perform three backup sets for daily, weekly, monthly schedule. Below is an example of 5 days GFS tape rotation below:

  • Daily full/ incremental backup on Mon-Thu, weekly full backup on Fridays, and a monthly full backup on the first Friday of the month.
  • Schedule a daily backup set to run weekdays (M-Thu). The Amanda strategy sets to “inconly” and a tape rotation cycle of 4.
  • Schedule a weekly backup set to do a backup on all Fridays except the first one in the month. The Amanda strategy sets to “noinc” and a tape rotation cycle of 5.
  • Schedule a monthly backup set to backup on the first Friday of the month. The Amanda strategy sets to “noinc” and a tape rotation cycle of 13.


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

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

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