In the example system, the SETSYS BACKUP(TAPE) command was used
to specify that all backups are to tape. In this environment, DFSMShsm
uses only tape daily backup volumes unless a volume backup command
specifies backup to DASD.
If you want DFSMShsm to use tape as a daily backup volume and you
have not specified restrictions limiting selection to tape, you must
define at least one tape for each of the appropriate days in the backup
cycle by using the ADDVOL command. You do not have to define tapes
as daily backup volumes with the ADDVOL command if you have restricted
daily backup volumes to tape by:
- Specifying BDC(TAPE) on a BACKVOL command
- Specifying BACKUP(TAPE) on a SETSYS command
If you use cartridge-type tape backup volumes, DFSMShsm writes
data on the tape in a single-file format.
DFSMShsm considers the following factors when it selects a tape
backup volume:
- Whether this is initial or subsequent volume selection
- For subsequent volume selection, the type of volume selection
you specified with the SELECTVOLUME parameter of the SETSYS command:
specific or scratch.