Hitachi TrueCopy for z/OS (T1711-96009, June 2006)

22 TrueCopy for the XP1024/XP128/XP12000/XP10000
Control Units (MCUs and RCUs)
The main control unit (MCU) and remote control unit (RCU) control the following TC390 operations:
• The MCU is the control unit (CU) in the main disk array that controls the M-VOLs of the TC390 volume
pairs. The Command View XP management station must be LAN-attached to the MCU of each TC390
pair. The MCU communicates with the RCU through the dedicated ESCON or Fibre Channel remote
copy connections. The MCU controls the host I/O operations to the TC390 M-VOLs as well as the
TC390 initial copy and remote copy operations between the M-VOLs and R-VOLs. The MCU also
manages the TC390 pair status and configuration information.
• The RCU is the CU in the remote disk array that controls the R-VOLs of the TC390 volume pairs. The
RCU assists in managing the TC390 pair status and configuration (for example, rejects write I/Os to
TC390 R-VOLs). The RCU executes the remote copy operations issued by the MCU. The secondary
Command View XP management station should be LAN-attached to the RCUs at the remote site. The
RCUs should also be attached to a host system to allow sense information to be reported in case of a
problem with a secondary volume or remote disk array and to provide disaster recovery capabilities.
118 TC390A – SIM notification when the TC390A sidefile reaches high-water mark (HWM = sidefile
threshold - 20%) (see mode 93).
Mode 118 ON: Generate SIM.
Mode 118 OFF (default): No SIM generated.
NOTE: The reported SIM when this mode is ON is not reported per CLPR.
308 Allows you to select whether the Remote Copy Path status, SIM218x, will be reported to the host or not.
Mode 308 ON: SIM218x will be reported to the host.
Mode 308 OFF: SIM218x will not be reported to the host.
464 TC390A – Allows you to select whether to generate SIM when the sidefile of TC390A, XRC Replication,
and CC reaches high-water mark (HWM = sidefile threshold - 20%. See mode 93). This mode takes
effect on the volume to which the inflow control is not set.
Mode 464 ON: Generate SIM.
Mode 464 OFF: No SIM generated.
The SIM is generated according to Mode 464 ON is the same as Mode 118 ON.
If both Mode 464 and Mode 118 are ON, the SIM will be generated for the volume that was detected
to have reached the high-water mark earlier.
NOTE: The reported SIM when this mode is ON is not reported per CLPR.
484 Allows you to select the indication type if you use the PPRC CQUERY command to display the remote
copy path status.
• Mode 484 ON: The status of path as using the fibre channel interface will be displayed.
WWNN will be indicated.
• Mode 484 OFF: The status of path as using an ESCON interface will be displayed.
WWNN is invalid.
NOTE: If the former type subsystem or the subsystem of TagmaStore USP microcode version
50-05-XX-XX or earlier is connected, mode 484 must be OFF.
Table 4 XP1024/XP128/XP12000/XP10000 modes for TrueCopy for z/OS (continued)
Mode Description