HP StorageWorks XP Remote Web Console Software - Manual (Page 18)

primary storage system. The primary storage system communicates with the secondary storage
system via the dedicated remote copy connections. The primary storage system controls the
host I/O operations to the Universal Replicator for Mainframe primary data volume and the
journal obtain operation of the master journal volume as well as the Universal Replicator for
Mainframe initial copy and update copy operations between the primary data volumes and
the secondary data volumes.
•
The secondary storage system is the control unit in the secondary storage system which controls
the secondary data volume of the Universal Replicator for Mainframe pairs and restore journal
volume. The secondary storage system controls copying journals and restoring journals to
secondary data volumes. The secondary storage system assists in managing the Universal
Replicator for Mainframe pair status and configuration (for example, it rejects write I/Os to
the Universal Replicator for Mainframe secondary data volumes). The secondary storage
system issues the read journal command to the primary storage system and executes copying
journals. The secondary Remote Web Console computer should be connected to the secondary
storage systems at the secondary site on a separate LAN. The secondary storage systems
should also be attached to a host system to allow sense information to be reported in case of
a problem with a secondary data volume or secondary storage system and to provide disaster
recovery capabilities.
The XP disk array can function simultaneously as a primary storage system for one or more primary
data volumes and as a secondary storage system for one or more secondary data volumes, provided
the remote copy connections and Fibre Channel interface ports are properly configured. The
Universal Replicator for Mainframe software allows you to specify the secondary storage system
from the connected primary storage system. Universal Replicator for Mainframe operations can
be performed on all LDEVs except for the XP command device. For further information on the XP
command device, see the HP StorageWorks XP for Business Continuity Manager Software User's
Guide.
NOTE: When you configure a Universal Replicator for Mainframe journal group pair, you have
to specify the serial numbers of the primary storage systems and secondary storage systems. You
have to specify different serial numbers for the primary storage system and secondary storage
system for the same Universal Replicator for Mainframe journal group pair. If you have to specify
the same serial number, contact your HP account team.
LDKC
The storage system is capable of having up to 510 CUs configured. The storage system manages
configurations that have more than 250 CUs by configuring two groups of CUs. Each group can
have up to 255 CUs defined. Each group is a storage system that logically exists in the XP disk
array (logical storage system). These groups are called a logical DKC or an LDKC. There is one
LDKC in the XP storage system; “00” has been assigned to the LDKC and 01 has been assigned
to the other LDKC.
Each LDKC controls 255 CUs; however, the number of CUs that can be used for XP program
products is up to 255. Therefore, the maximum number of volumes that can be used for XP program
products is 65,280.
Remote Copy Connections
The remote copy connections are the physical paths used by the primary storage systems to
communicate with the secondary storage systems. Remote copy connections enable communication
between the primary and secondary storage systems. The primary storage systems and secondary
storage systems are connected via Fibre Channel interface cables. You must establish paths from
the primary to the secondary storage system, and also from the secondary to the primary storage
system. Up to eight paths can be established in both of these directions.
When Fibre Channel interface (optical multimode shortwave) connections are used, two switches
are required for distances greater than 0.5 km (1,640 feet), and distances up to 1.5 km (4,920
18 About Universal Replicator for Mainframe Operations