StorageTek 6 manual Backup Backup Procedure

Backup

Backup Procedure

Backup of the control data set may be performed using conventions for specifying the secondary control data set and with copy data sets to enable block analysis, if desired. The following procedure describes steps for performing backups (see “JCL Examples” on page 247 for each step).

1.If OPTion(Analyze) is specified, allocate the SLSCOPY1 and SLSCOPY2 data sets. This step is not necessary if you specify OPTion(Copy). These data sets must be the size of the current control data set.

2.Allocate the SLSBKUP data set. It should be slightly larger than the control data sets. The size depends upon the number of discrepancies found. However, a recommended size is five percent larger than the current control data set.

3.Run the BACKup utility. If backup options requiring copy data sets are specified, the control data set’s volume is placed in a reserve state only long enough for the data to be copied to the SLSCOPYn data sets. The resident-host cannot access either control data set except for backup processing.

The library control data set is backed-up to the user-specified DASD data set. If journaling is enabled, all specified journals are reset when the backup is completed.

Note: Up to 99 journals can be specified per run.

Finally, the control data set is returned to a state where it can support normal library processing. If Analyze is specified, the SLSCOPYn data sets are processed using unreserved READs; otherwise, the utility ends.

4.If SLSCOPYn data sets are used and a return code of less than RC=8 (i.e., backup successful) is achieved, these data sets may be deleted or reused when the backup is restarted due to a failure.

When CDS Copies Are Split Among Hosts After an Error

Special precautions should be taken for running BACKup and RESTore when local/remote-linked libraries run control data sets independent of each other. In this situation, the primary and secondary control data sets are being updated by the HSC on their respective sides of the link. If remote communication is lost, the two control data sets become unsynchronized.

Precautions also should be followed when the link connecting the local and remote libraries is disrupted.

Special considerations while the link is down include:

•Keep enters and ejects of cartridges to a minimum. This practice reduces the number of AUDIT statements produced.

•Enter MNTD Float(OFf). This generates more pass-thrus, but less AUDIT statements.

•Enter MNTD SCRDISM(CURRENT) to avoid cartridge movement.

Chapter 4. Utility Functions 213

1st ed., 6/30/04 - 312579601