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

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
feet, 0.93 miles) are supported. If the distance between the primary and secondary sites is greater
than 1.5 km, optical single mode long wave interface connections are required. When Fibre
Channel interface (single-mode long wave) connections are used, two switches are required for
distances greater than 10 km (6.2 miles), and distances up to 30 km (18.6 miles) are supported.
See “Setting up Remote Copy Connections” (page 60) for further information on installing and
configuring the Fibre Channel remote copy connections.
The Universal Replicator for Mainframe remote copy configuration between the primary storage
system and secondary storage system has the following requirements:
•
Universal Replicator for Mainframe supports a 1-to-1 remote copy connection in one journal
group pair. In one journal group pair, one primary storage system can be connected to only
one secondary storage system. This configuration ensures the backup data consistency of two
or more volumes (for example, large databases) within the same storage system.
NOTE: HP strongly recommends that you establish at least two independent remote copy
connections from the primary storage system to the secondary storage system and vice versa to
provide hardware redundancy for this critical communications path.
Initiator Ports and RCU Target Ports
The initiator port and the RCU target port are required at both the primary storage system and
secondary storage system. The initiator port at the primary storage system is connected to the RCU
target port at the secondary storage system via the Fibre Channel interface. The initiator port at
the secondary storage system is connected to the RCU target port at the primary storage system.
The initiator port at the secondary storage system issues a read journal command to the primary
storage system, and then the RCU target port at the primary storage system sends journal data to
the secondary storage system in response to the read journal command.
18 About Universal Replicator for Mainframe Operations