Hitachi MP-96RD625-01 Logical DKC Ldkc, System and number 00 and 01 is assigned to each Ldkc

•The primary storage system is the control unit in the primary storage system which controls the primary data volume of the URz pairs and master journal volume. The Storage Navigator remote console PC must be LAN-attached to the 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 URz primary data volume and the journal obtain operation of the master journal volume as well as the URz 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 URz pairs and restore journal volume. The secondary storage system controls copying of journals and restoring of journals to secondary data volumes. The secondary storage system assists in managing the URz pair status and configuration (e.g., rejects write I/Os to the URz secondary data volumes). The secondary storage system issues the read journal command to the primary storage system and executes copying of journals. The secondary Storage Navigator PC 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 USP V 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 URz software allows you to specify the secondary storage system from the connected primary storage system. URz operations can be performed on all LDEVs except for the USP V command device. For further information on the USP V command device, please refer to the Business Continuity Manager User and Reference Guide.

Note: When you configure a URz journal group pair, you have to specify the serial numbers of primary storage systems and secondary storage systems. You have to specify the different serial numbers of primary storage system and secondary storage system for the same URz journal group pair. If you have to specify the same serial number, please contact your Hitachi account team.

Logical DKC (LDKC)

	The USP V storage system controls the CU (Control Unit) by dividing the CUs
	in to groups of 255 CUs. Each group is a storage system that logically exists in
	USP V (logical storage system). These groups are called a “logical DKC” or an
	“LDKC (Logical disk controller)”. There are 2 LDKCs in the USP V storage
	system and number “00” and “01” is assigned to each LDKC.
2-8	Chapter 3 Preparing for Universal Replicator z/OS Operations

Hitachi Universal Replicator for IBM /OS User’s Guide