HPE XP for Compatible Parallel Access Volumes Software (PAV) and HPE XP for Compatible Hyper PAV Software enable high performance concurrent access of mainframe volumes by permitting a mainframe host system to issue multiple I/O requests in parallel to individual logical devices within the HPE XP Disk Array. Without PAV, mainframe systems can initiate only one I/O request per device at a time, and must wait for the I/O to complete before starting another I/O request to the same device. By utilizing alias addresses that all point to the same device as the base address, PAV enables the host system to start several I/O requests simultaneously to the same device, thus greatly improving performance.
The XP Disk Array supports static PAV, dynamic PAV, and Hyper PAV. With static PAV, the number of aliases assigned to each base device does not change. With dynamic PAV, high workload base devices can borrow idle PAV aliases from other base devices, increasing their I/O capability.
- HPE XP for Compatible Hyper PAV Software is now available for the HPE XP24000, XP20000, XP12000, XP10000 Disk Arrays.
By permitting multiple paths to the same logical device, HPE XP for Compatible Parallel Access Volumes Software greatly enhances the performance of data accesses to the HPE XP Disk Array by mainframe hosts.
XP for Compatible Hyper PAV enhances the efficiency of PAV by selecting the alias IDs from a pool and binding them to base IDs only for the duration of the I/O operation. Since the pool allows fewer aliases than are required for conventional PAV, more addresses are available for use as base devices.