What are backup strategies?

A Backup Strategy, also referred to as a Media Rotation Strategy, refers to the usage, re-usage and rotation of media in Backup Exec. Some of the most common strategies are: Son, Father/Son, and Grandfather/Father/Son. There are many other strategies but this article will focus on these examples. The main differences between strategies, is the number of media required and the retention period before media is put back into the media rotation.

Common Backup Strategies

Son Backup Strategy:
This involves performing a full backup every day. This is a simple strategy to administer but is not particularly effective, as it leaves the tapes more prone to wear and tear due to the high level of usage for each tape used. Performing a full backup daily also requires a larger window of operation for the backup process which increases the probability of failure.

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Father/Son Strategy:
This strategy combines the use of full backups and either incremental* or differential** backups over a two week period. The initial backup required is a full backup, after which four media are used for Monday through Thursday either using incremental or differential backups. Two further media are used for full backups on Fridays and are often stored offsite. This strategy is easy to administer and allows for longer data retention periods than the Son Strategy. However, this strategy typically does not meet the needs of most organisations for data retention periods.

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Grandfather/Father/Son Strategy:
In this strategy, four media are used to perform incremental or differential backups for Monday through Thursday (initially a full backup is required). Three tapes are then used for full backups on Fridays and sent offsite. Another twelve tapes are used for monthly full backups on the last Friday of each month which are sent offsite for secure storage. This is one of the more common backup strategies due to the relative simplicity to administer and longer retention period. This strategy is also easy to modify to incorporate more tapes if required.

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Summary

While these strategies are the typical examples, they are only a selection of some of the possible backup strategies and configurations that can be implemented. The backup rotation a company uses should be one that suits its needs and expectations for data backup, and retention. At Computer Concepts Limited, we have a team of experienced and dedicated Engineers who can discuss and implement backup strategies to suit a company’s requirements. If you do not have a backup strategy in place, or you have any questions regarding the effectiveness of your current backup strategy, contact us to see what we can do to assist you.

**Differential Backups: A Differential Backup backs up only the data that has changed since the last full backup. For example, if a full backup is done on Monday and a differential on each subsequent weekday, then each differential would need to backup data that has changed since the full backup on Monday.

*Incremental Backups: An Incremental Backup backs up only the data that has changed since the last full OR incremental backup. For example, if a full backup is done on Monday and an incremental backup on each subsequent weekday, then each incremental would only need to backup data that has changed since the previous day’s full or incremental backup.

Note: This article is written with a focus on Symantec Backup Exec version 12.0 and using the Symantec Backup 12.0 Administrators Guide.