HP XP7 Continuous Access Journal User Guide (TK911-96002)

• Up to 65,280 volumes can be used for volume pairs.
• XP7 and P9500 or XP24000/XP20000 Disk Array can be set up in 3-data-center (3DC)
cascade or multi-target configurations. These configurations are used when combining
Continuous Access Synchronous and Continuous Access Journal systems. See “Configurations
with Continuous Access Synchronous” (page 124) to review these configurations. There are no
restrictions for combining primary and secondary sites between XP7 and P9500 or
XP24000/XP20000 Disk Array.
Guidelines for preparing systems for Cnt Ac-J
Use the following guidelines to ensure that your XP7 systems are ready for Cnt Ac-J:
• Identify the locations where your Cnt Ac-J primary and secondary data volumes will be located,
then install and configure the XP7 systems.
• Make sure that primary and secondary systems are configured for Remote Web Console
operations.
For more information, see HP XP7 Remote Web Console User Guide .
• Make sure that primary and secondary systems are properly configured for Cnt Ac-J operations,
for example, cache memory considerations. See the entry for Cache and Nonvolatile Storage
in the requirements table, “System requirements” (page 15). Also consider the amount of
Cache Residency data to be stored in cache when determining the required amount of cache.
• Make sure that primary and secondary systems have the system option modes specified that
may be required for your Cnt Ac-J configuration. See “System option modes ” (page 30),
below, for more information.
• Make sure that primary systems are configured to report sense information to the host. Remote
systems should also be attached to a host server to enable reporting of sense information in
the event of a problem with an S-VOL or secondary system. If the secondary system is not
attached to a host, it should be attached to a local site host server so that monitoring can be
performed.
• 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 secondary
system is not powered off during Cnt Ac-J operations.
• Install the Cnt Ac-J remote copy connections (cables, switches, and so on) between the primary
and secondary systems.
• When setting up data paths, distribute them between different storage clusters and switches
to provide maximum flexibility and availability. The remote paths between the primary and
secondary systems must be separate from the remote paths between the host and secondary
system.
System option modes
To provide greater flexibility, the XP7 Storage has additional operational parameters called system
option modes (SOMs) that allow you to tailor the XP7 to your unique operating requirements. The
SOMs are set on the SVP by your HP representative.
The system option modes can be used for several kinds of Cnt Ac-J customizations, including:
• 2DC configuration
• Delta resync configuration
• Configuring split options for mirrors
• Improving initial copy time
30 Planning volumes, XP7 systems