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

Concurrent Read Access to Virtual Volumes Created by CA Disk

Most tape media can only be mounted on one device at a time forcing 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 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 fully exploits AllowConcurrentVVERead Access. Other CA Disk utilities exploit AllowConcurrentVVERead but may require your automation software to respond WAIT to message IEF690I if simultaneous allocations for the same Virtual Volume occur.

This allows you to write CA Disk ARCHVOLS to CA Vtape Virtual Volumes and to benefit not only from tape utilization efficiencies but also operational performance improvements during disaster recovery and day-to-day storage management processes.