Our story begins as our stories usually do, somewhere in the middle after the customer has been working on a problem, in this case low throughput to virtual tape, for a while and they are just about to give-up.
The customer had a group of tape jobs that frequently would not finish on time. On time means the jobs complete within the batch window. Not on time means they would run beyond the batch window and would compete with the online activity. Some days the job would run in less than an hour, while the same job on other days would run for 10 to 15 hours.
Low Throughput to VSM Tape Systems
The customer investigated the issue when the jobs ran long and found that the throughput to the VSM tape systems was low for the jobs in question. A joint investigation with Oracle was started under the assumption that the problem was caused by the VSM tape systems. My intel tells me that 6 people from the customer worked on the investigation for a whole month and Oracle was unable to find anything wrong from a hardware or software perspective.