I recently had the same problem but on a z/OS 1.4 running on a z800 at a client site. They had a 3494 ATL with 3590 tapes and certain "J"s would take in excess of 10 minutes to apparently come to load point even though one could look inside and see the tape mounted etc. The problem only seemed to happen to certain HSM migration tapes on J cartridges and would manifest itself wit h a message: ARC0310A "Can tape <volser> be mounted?. Reply Y or N" It turned out that it was a performance tuning issue. The Workload Manage r Service Policy velocity for the HSM Started task was way too low so when
the system was very busy it would take over ten minutes before HSM, which was the application using the tape, to get control again. I didn't clue in at first. Instead I tried to figure out why certain "J" tapes used by HSM would have this problem. A SLIP TRAP svc dump of the ARC0310A revealed HSM to have a very low dispatching priority at that point in time. I realize this is a VM system you are running on but the service machine of the product using the tape drive (VMBACKUP maybe) and it's priority would be analogous to the the HSM started task and its WLM velocity on z/OS. Hope this helps..... Dave Ross AA Technologies Inc. Toronto 416-252-2192
