Hitachi TrueCopy for IBM z/OS User and Reference Guide (T5211-96001, June 2007)

About TrueCopy for z/OS Operations 2-11
Hitachi Universal Storage Platform V TrueCopy for IBM z/OS User’s Guide
Initiator Ports and RCU Target Ports
The initiator ports are the dedicated fibre-channel interface ports on the main
storage system (MCU) to which the RCUs (RCU target ports) are connected.
The initiator ports connect to the RCUs to send write I/O operations directly to
the RCUs. Any fibre-channel interface port of the USP V can be configured as
an initiator port. The TrueCopy for z/OS software allows you to change the
configuration of the USP V fibre-channel ports (ordinary target port, initiator
port, or RCU target port) as needed.
The RCU target ports are the dedicated fibre-channel interface ports on the
remote storage system (RCU) to which the MCU (initiator ports) are
connected. Any fibre-channel interface port of the USP V can be configured as
an RCU target port. The RCU target ports can be connected to the host
channel paths via the fibre-channel switch.
To fully support an automated environment, the USP V automatically
configures a fibre-channel port as an initiator or RCU target if required in
response to the TSO CESTPATH and CDELPATH commands. See system option
mode 114 in Table 2-2.
Note: For fibre-channel interface, do not use the CESTPATH and CDELPATH
commands at the same time as the SCSI path definition function of LUN
Manager.
Note: Two or more initiator ports must be configured before you can add the
RCUs and create the TCz pairs. The initiator ports cannot communicate with
the host processor channels. To enable the host processor channels to send
write I/O operations to the MCU, the host channel paths must be connected to
the other fibre-channel interface ports in the MCU. Ordinary fibre-channel
interface ports cannot be connected to the MCU. These ports (usually called
target ports) can be connected to the host processor channels only.