HP XP7 Storage - Manual (Page 28)

3 Planning for Continuous Access Synchronous Z
This chapter provides information and instructions for planning primary and secondary system,
pair volumes, data paths, and other elements.
Storage system preparation
The following preparations are required for the storage systems in a Continuous Access Synchronous
Z pair relationship.
•
You can pair the volumes on XP7 Storage with volumes on another XP7, P9500, or
XP24000/XP20000 Disk Array. However, if pairing with volumes on an earlier model, see
the restrictions in
“Requirements for XP7 with earlier model storage systems” (page 29) .
•
Remote Web Console must be LAN-attached to the primary and secondary system. See the
HP XP7 Remote Web Console User Guide for information.
•
The primary and secondary system must be set up for Continuous Access Synchronous Z
operations. See
“Cache, additional shared memory requirements” (page 28) and “DASD fast
write requirements” (page 29) . Make sure to consider the amount of Cache Residency data
that will be stored in cache when determining the amount of cache for Continuous Access
Synchronous Z operations.
•
Set the system option modes, if needed, for your Continuous Access Synchronous Z
configuration on the primary and secondary system. See
“S-VOL Read and other system
options” (page 29) for more information.
•
Make sure that the primary system is configured to report sense information to the host. The
secondary system should also be attached to a host server to report sense information in the
event of a problem with an S-VOL or secondary system. If the storage system is not attached
to a host, it should be attached to a primary system host server so that monitoring can be
performed.
•
On the host operating system, make sure that the missing interrupt handler (MIH) value (also
called host I/O patrol time) is set high enough to accommodate the number of pairs, the cable
length between the primary and secondary system, and the initial copy pace. The recommended
MIH value for Continuous Access Synchronous Z operations is 60 seconds. For MVS, the MIH
value is specified in the SYS1.PARMLIB file. The recommended MIH value for Compatible XRC
is different than for Continuous Access Synchronous Z. If you are performing Continuous
Access Synchronous Z and Compatible XRC operations on the same storage system at the
same time, contact your HP representative for assistance.
•
If power sequence control cables are used, set the power select switch for the cluster to LOCAL
to prevent the primary system from being powered off by the host. Make sure the S-VOL is
not powered off during Continuous Access Synchronous Z operations.
•
Install the data path between the primary and secondary system. Distribute data paths between
different storage clusters and extenders or switches to provide maximum flexibility and
availability. The remote paths between the primary and secondary system must be different
than the remote paths between the host and secondary system. See
“Data path requirements
and configurations” (page 46) for more information.
Cache, additional shared memory requirements
Cache must be operable for the pair’s primary and secondary system, otherwise pairs cannot be
created. The secondary system cache should be configured to adequately support Continuous
Access Synchronous Z remote copy workloads and any local workload activity.
Additional shared memory is prerequisite in both of the primary and secondary system.
28 Planning for Continuous Access Synchronous Z