Administration Guide › Managing Configuration Options › Defining Tape Handling Procedures › Overriding Tape Expiration Dates

Overriding Tape Expiration Dates

When an output tape is mounted for use in a CA VM:Backup backup or MPC job, CA VM:Backup verifies the following information about the tape:

• The labels on the tape are valid.
• The tape is either expired or new.
• The tape can be used in the job.

If the tape can be used in the job, the product rewrites the tape labels to reflect the new information for this backup or MPC job. The new information includes a new tape expiration date. However, only the tape labels are updated now; the resource pool information is updated when the job completes. If the job does not run to completion, the labels reflect that the tape is in use and is not expired. However, the resource pool indicates that the tape is either expired or new.

CA VM:Backup uses the resource pool information to select volumes to use in backup or MPC jobs; CA VM:Backup will select this tape for a future backup or MPC job because the resource pool indicates that the tape is either expired or new. When the tape is mounted, CA VM:Backup will determine from the tape labels that the tape is not expired.

To indicate how you want CA VM:Backup to handle unexpired tapes that are mounted during backup or MPC jobs, select either the Yes or No response to the following question on the Define Tape Handling Options screen:

Can operators override expiration dates on tape volumes?

Yes

The tape operator is authorized to overwrite unexpired tapes. When an unexpired tape is mounted during a backup or MPC job, the product issues messages to the tape operator requesting permission to overwrite it.

No

The product does not ask for permission to overwrite the unexpired tape. Instead, CA VM:Backup rejects the tape, selects another volume to use in the job, and asks the tape operator to mount the new volume. If the product is configured to enable tape chaining in tape trailer labels, before making the mount request, CA VM:Backup may ask the tape operator to mount the previously used volume again. Mounting the volume again lets CA VM:Backup update its trailer label to reflect the newly selected volume.

Notes:

• For more information about updating the VMBACKUP CONFIG file to configure this option, see the section "TAPEXPDT Record" in the System Programmer Reference Guide.
• For more information about tape chaining, see the section "Managing Tape and DASD Resources" section in the System Programmer Reference Guide.

Overwriting Existing Data Sets

If CA VM:Backup is interfaced with CA VM:Archiver, whether or not operators are allowed to override tape expiration dates determines whether CA VM:Backup issues messages to the tape operator requesting permission to overwrite existing incomplete data sets.

CA VM:Archiver tapes can contain multiple data sets. Each data set on the tape contains its own tape header labels. A valid data set is any data set that contains valid header labels.

The following section describes the ways in which CA VM:Archiver protects its tapes from being inadvertently used.

Tape expiration date

All CA VM:Archiver tapes have an expiration date of PERM (permanent), which means that they never expire. The PERM designation protects tapes from becoming scratch tapes and from being reused by other users.

Ownership

All tapes that are created for CA VM:Archiver jobs are owned by the CA VM:Archiver service virtual machine that submitted the jobs. CA VM:Backup ensures that the requesting user is the owner of the tape before it uses the tape.

Data set

CA VM:Archiver tells CA VM:Backup which data sets to write to so that CA VM:Backup does not inadvertently overwrite a CA VM:Archiver data set.

When appending data sets to a tape, CA VM:Archiver may provide CA VM:Backup with a starting volser for that job. CA VM:Archiver always asks CA VM:Backup to write a specific data set. If the job is canceled while CA VM:Backup is processing it, part of the data set might be written to the CA VM:Archiver tape volume. Therefore, correct and valid header labels may exist. When CA VM:Archiver submits the next job, it asks CA VM:Backup to write the same data set that was specified in the canceled job. However, when CA VM:Backup encounters the valid tape header labels, it assumes that the entire data set exists.

If you select Yes in response to the question, Can operators override expiration dates on tape volumes? on the Define Tape Handling Options screen, the tape operator is authorized to overwrite existing incomplete CA VM:Archiver data sets. Therefore, CA VM:Backup asks the tape operator for permission to overwrite such data sets. If you select No in response to this question, CA VM:Backup selects another tape volume to use in the job.

Note: For information about updating the VMBACKUP CONFIG file to configure this option, see the "TAPEXPDT Record" section in the System Programmer Reference Guide.