The “FastDPAV” function, an optimized DPAV, is offered for Server Units SU /390 that support a modification of the logical unit number (LUN) for alias devices when starting an I/O. For these Server Units, DPAV is no longer recommended. For FastDPAV, also see the “System Administration” manual [5].
FastDPAV does not require monitoring of the device utilization and the switchover of alias devices by IORM, but it requires an activation using DPAV_SET_ON=YES.
Activation of FastDPAV alias devices (using DPAV_DEV_ADD) is not necessary.
However, querying the I/O rate for FastDPAV alias devices (using DPAV_CHK_ALI) is supported.
By default, all FastDPAV base devices are taken into account for using FastDPAV alias devices. The DPAV_BAS_REM statement can be used to exclude FastDPAV base devices from using FastDPAV alias devices.
They can be included again, using DPAV_BAS_ADD. At the same time, the maximum number of aliases per disk can be modified. The default value is the same as the maximum value of 7.
For FastDPAV, the previously executed IORM statements are entered and executed in the respective local BS2000 system.