TAPECOPY command

The TAPECOPY command allows you to make copies of single-file-format, DFSMShsm-owned tapes. The copies are known as alternate tapes and are identified in the offline control data set (OCDS) as alternates to the tapes that are copied.

DFSMShsm provides commands to copy categories of DFSMShsm-owned tape volumes:

TAPECOPY BACKUP
 
TAPECOPY MIGRATIONLEVEL2
 
TAPECOPY ALL

These commands cause DFSMShsm to make alternate copies of full, single-file-format tapes that do not already have an alternate copy. The TAPECOPY MIGRATIONLEVEL2 and TAPECOPY ALL commands also cause DFSMShsm to make alternate copies of partially full ML2 tapes if the environment is PARTIALTAPE(MIGRATION(MARKFULL)).

You can make copies of all volumes categorized as either ML2, backup (or both), or of individual tape volumes. You can issue one TAPECOPY command per DFSMShsm host as long as the requests do not overlap. For example, you can issue a TAPECOPY ML2 command on one host and a TAPECOPY BACKUP command on another.

For individual tape volumes, you can make copies of either partial or full volumes, and of volumes with or without an alternate copy already existing.

The TAPECOPY command provides for copying only cartridge-type, single-file-format tapes. If you have data on multi-file format tapes (such as reel tapes), you can transfer the data onto new cartridge tapes by using the recycle function. These cartridge tapes can then be copied, and use of the reel tapes can be discontinued.

The output or alternate tape volumes used by the tape copy process begin as scratch tape volumes. These scratch tape volumes cannot be volumes that have been added to DFSMShsm with the ADDVOL command. Using scratch tape volumes not added to DFSMShsm eliminates backup, dump, or ML2 tape volumes from being used as alternate tape volumes.

DFSMShsm copies the security information (RACF® and expiration date) of the original volume, or you can specify a different expiration date when an alternate volume is created. Because password protection is not copied to an alternate volume, you should use RACF or an expiration-date protection for the alternate volume. If the alternate volume is in the RACF DFSMShsm tape volume set, the RACF protection is removed from the alternate volume when it is returned to scratch status. If the tape resource class (TAPEVOL) is inactive during a recycle request for a RACF-protected original volume with an alternate, the RACF protection for the alternate will be deleted based on the TTOC information available for the original volume.

Information about the alternate tape volumes is stored in the tape table of contents (TTOC) records of the OCDS. While, over time, a given tape volume might be copied to several alternate volumes, only the most current alternate tape volume reference is stored in the TTOC record.

Attention: Be aware that some tape management products do not protect DFSMShsm data tapes from being mounted for output in response to a nonspecific mount PRIVAT request, and therefore they can allow DFSMShsm to write over some of its own tapes. This exposes alternate tapes because DFSMShsm does not maintain a way to quickly identify an alternate tape as a DFSMShsm tape, so there is no check to prevent an alternate from being overwritten. DFSMSrmm does not have this exposure.

Assigning expiration dates to tapes provides only partial protection from inadvertent rewriting over valid data. The general solution is to use policies defined with a function like "vital record specifications" in a tape management product like DFSMSrmm . DFSMShsm uses tape-volume exit ARCTVEXT to communicate to tape management products, except DFSMSrmm, when a tape can safely be returned to scratch status.

TAPECOPY command

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