Customize Virtual Device Engine › Concurrent Read Access to Virtual Volumes Created by CA Disk

Concurrent Read Access to Virtual Volumes Created by CA Disk

You can mount most tape media on only one device at a time. This forces applications like CA Disk to serialize tape access when accessing multiple files that reside on the same tape volume (CA Disk ARCHVOL). For instance, multiple DMSAR subtasks or batch Restore jobs that are directed to restore different user DASD files residing on the same tape volume, must wait and access the tape volume one at a time.

If you are running on a JES2 system, you can enable concurrent read access to CA Disk ARCHVOLS that reside on Virtual Volumes. Set AllowConcurrentVVEReadAccess to CADISK in the Dynamic Options Section of the OSPARMS Parmlib member.

Note: CA Disk ARCHVOL Restore processing exploits AllowConcurrentVVERead Access. Other CA Disk utilities exploit AllowConcurrentVVERead. If simultaneous allocations for the same Virtual Volume occur, the utilities can require your automation software to respond WAIT to message IEF690I.

Concurrent Read Access lets you write CA Disk ARCHVOLS to CA Vtape Virtual Volumes. You benefit from tape utilization efficiencies and operational performance improvements during disaster recovery and day-to-day storage management processes.