HP StorageWorks Continuous Access XP user guide for the XP10000/XP12000 (December 2005)

34 Continuous Access XP for the XP10000/XP12000
Ensure that adequate cache is installed and available for all open systems and mainframe
asynchronous mirroring operations. Also consider the amount of HP Cache LUN XP data to be stored in
cache when determining the required amount of cache.
4. HP representative: Ensure that MCUs are configured to report sense information to hosts. RCUs should
also be attached to a host server to enable reporting of sense information if a problem with an S-VOL
or RCU occurs. If the remote site is unattended, RCUs should be attached to a host server at the primary
site, so the system administrator can monitor operational condition of RCUs.
5. HP representative: If power sequence control cables are used, set the power select switch for the cluster
to LOCAL to prevent the host from powering off the MCU. Also ensure that the RCU will not be powered
off during Continuous Access XP operations. See ”Powering off and on Continuous Access XP
components” on page 104 for further information.
6. HP representative: For Fibre Channel interface connections, install the Fibre Channel adapter features.
For serial interface connections, install the serial port adapter features. If the MCU and RCU are
multiplatform disk arrays, serial interfaces might be available, and additional serial port adapter
features might not be required.
7. HP representative: Install the Continuous Access XP remote copy connections between MCUs and
RCUs. The user supplies this hardware (optical fibre cables, switches, ESCON cables, and so on). See
”Fibre Channel remote copy connections” on page 34 for remote copy configurations. Distribute paths
between different storage clusters and switches to provide maximum flexibility and availability. Logical
paths between the MCU and RCU must be separate from logical paths between the host and RCU. For
Fibre Channel and serial interface connections, only Continuous Access XP activities (Sync and Async)
can share the same direct connect or switch zoned fibre remote copy connections (future support will
eliminate this restriction).
Fibre Channel remote copy connections
Figure 5 shows remote copy connection configurations for Fibre Channel interface Continuous Access XP
operations. The MCU and RCU of each Continuous Access XP pair must be connected via multimode
shortwave optical fibre cables. For multimode shortwave optical fibre cables, fibre cables up to 1.5 km in
length and up to two switches are required for distances greater than 0.5 km. For single-mode longwave
optical fibre cables between two switches, fibre cables up to 11 km in length can be used
(.5km+10km+.5km). Using DWDM between two FC switches can allow a distance of 80km or more.
Long-distance solutions are provided using approved channel extenders and communication lines.
Figure 5 Fibre Channel remote copy connections
NOTE: For Fibre Channel interface connections, use the switches as ordinary switch connections. No
special settings are required for the XP10000/XP12000.