The percentage full seems to be going up. Do I need to increase the size of this disk?
There are several variables in determining the amount of disk space needed. The number of catalogs and their retention period is also an important factor in determining the disk size. The BKUP disk contains data used for and during the backup/restore process. The RETPD that you specify in your jobs, is the retention period for tapes and records in the backup catalogs.
Each time a backup job runs, VM:Spool creates or updates a catalog file and maintains it on the BKUP minidisk. The catalog file contains a record of which files were written to which tapes. If the job name is DISASTER, the catalog file, by default, will be DISASTER CATALOG.
VM:Spool manages the catalogs automatically. After an incremental backup has updated a catalog file, VM:Spool includes files backed up in the most recent run and all files previously recorded in the catalog which have not yet reached their expiration date.
For a full backup, VM:Spool creates a new catalog and erases any previous catalog by the same name.
VM:Spool does manage this disk space, although, it is a good idea to estimate up when calculating the amount of disk space needed.
Refer to the SYSTEM Record in VM:Spool's System Administrator's Guide for information about setting thresholds for reporting of disk-full conditions of the AUDT, DBAS and BKUP minidisks.