The Grandfather media rotation strategy requires the following:
Table: Grandfather media rotation strategy
|
Item |
Description |
|---|---|
|
Number of media required |
19 (minimum) |
|
Overwrite protection period |
One year |
The Grandfather method is one of the most common media rotation strategies. It is simple to administer and comprehensive enough to allow easy location of files when they need to be restored.
In the Grandfather scenario, four media are used Monday through Thursday for incremental or differential backups; another three media are used every Friday for full backups.
The remaining 12 media are used for monthly full backups and are kept offsite.
The Grandfather strategy is recommended because it offers a good media number to storage life ratio (19 media/1 year). It is also easy to modify if you want to incorporate more media. For example, you could perform a full backup on the last Saturday of the month to keep permanently.