System Components and Execution › CA TLMS Major Features › Extended System Failure Protection

Extended System Failure Protection

CA TLMS automatically provides extended tape data set protection against catastrophic system failure for all tape data sets at OPEN for output time:

• CA TLMS changes the scratch status to NONSCRATCH and the data set name to TLMSII-CRASH-PROTECTED in the Volume Master File at OPEN for output time.
• The data set name is changed to the actual data set name when the data set is closed and normal CA TLMS updates are made. By updating in this sequence, volumes mounted for output data sets are marked NONSCRATCH when processing starts. If an operating system failure occurs during the processing of the jobs, the volumes currently in use are protected against reuse when the operating system is restarted. The same job (job name) will be allowed to use the volumes for output without changing the scratch status of the volume.
• The special identity inserted in the data set name aids in identifying volumes in use when a system failure occurs. These volumes must be manually changed to SCRATCH status before they can be reused for output by another job.

If you do not want extended protection for all tape data sets, specify the system option PROTECT=SELECT; this restricts protection to selected data sets only. Then, select the data sets to be "crash-protected" by coding SPACE=(1,(1,2)) on their DD statements.

Note: Crash protection applies only to file 1 on a multi-data set volume or set of volumes.

Note: The special identifier remains in the data set name field if no 'CLOSE' event is intercepted. This may occur for reasons other than a system crash.