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Summary



One commonly used tape rotation scheme is Grandfather-Father-Son. This scheme uses three sets of tapes for daily, weekly and monthly backup sets.

Resolution



To implement the Grandfather-Father-Son rotation scheme, you will need three sets of media. The actual number tapes required in each media set will vary depending on how much data you need to backup.

  • The first set, "Son" represents your daily backups. These tapes will be used to run daily incremental (or differential) backups and can be reused weekly.
  • A second set called "Father" is used to run full backups on the day in which you do not run a daily backup. This media set can be reused monthly.
  • The final set of tapes, called "Grandfather," is used to perform full backups on the last business day of each month and can be reused quarterly.

This rotation scheme will backup data on a daily, weekly and monthly basis. In some instances, archived data is required for periods longer than one quarter. In these cases, the tapes are usually stored off-site.

To implement this scheme in Backup Express, create two jobs with four media pools as described below:

  1. Grandfather: A job with a custom schedule to run as a base on the last weekend of the month, with 90 day retention (media pool = Gfpool) and to run as an incremental or differential on the weekdays the week after the base. The incremental/differential retention period should be set to 30 days (media pool = Son2pool).
  2. Father: A job with a built-in base/incr or base/difr schedule, running the base on weekends (excluding the last weekend) and with a 30 day retention period (media pool = Fpool and running the incr/difr on weekdays after the father base backups, with 7 day retention (media pool = Son1pool) and excluding the days in which the grandfather incremental/differential runs are made.

You may want to set as holidays the days in which the Grandfather job runs and select to "keep schedule" on holidays for that job. You will then not need to exclude runs for the Father job as long as the "skip run" is set for holidays on the Father job. To schedule the Grandfather job, manually select the appropriate day for the last weekend in every month (set the schedule years in advance).

To restore data from these jobs, you will need to load both Gfpool +Son2pool or Fpool + Son1pool tapes into the jukebox unless you are restoring data from a base only.