HP Mainframe Connectivity Design Guide

GDPS/PPRC and GDPS/XRC command support
Most XP storage systems can be integrated into a GDPS/PPRC or GDPS/XRC environment. The
GDPS features that are supported depend on the XP storage system model. For more information,
contact an HP storage representative.
Parallel access volumes
PAVs enable a single LPAR to issue multiple I/O requests in parallel to a disk volume. Volumes
with a base address contain data. PAVs are alias addresses assigned to the volume, in addition
to the volume's base address. Therefore, multiple addresses can point to the same volume and
data, allowing I/O operations to run concurrently with the same volume. For example, the mainframe
can issue up to four I/O operations concurrently to a volume that has one base address and three
PAV addresses.
PAV addresses are included in the total number of addresses (volumes) that the XP storage system
supports. Table 76 (page 115) lists the number of PAVs supported for each base address in an XP
storage system.
Table 76 XP PAV support
Number of PAVs
nl
CU typeXP model per base address
2552105XP10000/12000/20000/24000
152105XP1024/128
Multiple allegiance
MA enables multiple LPARs to issue multiple I/O requests in parallel to a disk volume. MA is a
standard part of the XP array and the PAV feature.
Hyper PAV
Hyper PAVs build on the PAV and MA functions. The difference is that instead of fixed alias
addresses configured for each base address, Hyper PAV allows a pool of alias addresses to be
used and reused to access base addresses. This means that fewer alias addresses need to be
configured because each alias address can be assigned dynamically to a base address as needed.
The mainframe IOS manages the Hyper PAV pool, assigning (or binding) an alias address to a
base address for the duration of a single I/O command. After the I/O completes, the alias address
is released, and it is available to be bound to another base address when needed.
Table 77 (page 115) lists the XP models and CUs that support Hyper PAV.
Table 77 Hyper PAV support
Maximum number of Hyper PAVs per LCUCU typeXP model
255
1
2107
XP20000/24000
1
The actual number required for your workload is typically much less.
XP mainframe addressing of volumes 115