GFS Media Pools

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GFS Media Pools

Grandfather-Father-Son (GFS) Rotation media pools are based on basic media pooling architecture.

GFS Rotation jobs use three media pools: Daily, Weekly, and Monthly, which are based on the information you enter in the Media Pool Name Prefix field when submitting the job.

When a GFS Rotation job runs, Arcserve Backup automatically formats and names your media according to the backup type, media pool, and date using the following syntax:

(backup type)-(user-defined media pool prefix)-(day-of-the-week)-(date)

Where..	Is…
backup type	F - full backup I - incremental backup D - differential backup W - weekly backup M - monthly backup A - all daily backups (full, incremental, and differential) when you use the Media Maximization option (enabled by default) and enable the Append Media option. For more information on the Media Maximization option, see the section Media Maximization in GFS Rotation Jobs.
user-defined media pool prefix	The name you assigned to the media pool for your GFS Rotation scheme.
day of the week	An abbreviation for the day of the week on which the job was performed.
Date	The date on which the backup was performed in mm/dd/yy format.

This media naming convention allows you to easily identify backup media. For example, the media used for the first full backup in your rotation scheme will have the following name: F TP MON 11/1/05.

Note: Arcserve Backup prevents you from using the underscore character ( _ ) and the hyphen character ( - ) when specifying Media Pool names.

Five-day rotation schemes have the following retention times for each media pool:

Daily (_DLY)--six days (daily media in seven-day Rotation Schemes have a retention time of eight days)
Weekly (_WLY)--five weeks
Monthly (_MLY)--343 days

The following are the formulas used for calculating the number of media in the Save Sets and the retention times for the GFS media pools:

Daily pool--This pool holds the media for daily backup jobs. The default retention period is six days and the number of Save Set media is based on the number of daily media in the GFS Rotation minus one [# of daily media -1].
Weekly pool--This pool holds the weekly media. The retention period equals the number of weekly media times seven, minus one [(# of weekly media * 7) - 1]. The number of save media is based on the number of weekly media in the GFS setup minus one [# of weekly media - 1].
Monthly pool--This pool holds the monthly media. The retention period equals the number of monthly media times 29 minus five [(# of monthly media * 29) - 5]. The number of save media is based on the number of monthly media in the GFS setup minus one [# of monthly media - 1].

More information:

Media Maximization in GFS Rotation Jobs