HP StorageWorks XP Remote Web Console Software - Manual (Page 22)

22 Hitachi TrueCopy z/OS for HP XP12000/XP10000 and SVS 200 storage systems
CAUTION: Do not use M-VOLs or R-VOLs from hosts that have different CU emulation types (2105 or 2107,
and 3990) at the same time. If you use the M-VOLs or R-VOLs from the 2105 or 2107 and 3990 hosts
simultaneously, an MIH message might be reported to the 3990 host.
Remote copy connections
The remote copy connections are the physical paths used by the TC390 MCUs to communicate with the
TC390 RCUs. The maximum number of physical paths per logical CU image is eight for Fibre Channel,
eight for serial with 2105 emulation, and four for serial with 3990 emulation. The MCUs and RCUs are
connected through the serial interface (ESCON) or Fibre Channel interface cables.
When serial interface connections are used, ESCON directors (ESCDs) and/or ESCON repeaters are
required for distances greater than 3 km (1.9 miles). TC390 operations can be performed at distances of
up to 43 km (26.7 miles) using standard ESCON support. When using Fibre Channel interface (multimode
shortwave) connections, two switches are required for distances greater than 0.5 km (1,640 feet).
Distances up to 1.5 km (4,920 feet, 0.93 miles) are supported.
When using Fibre Channel interface (single-mode longwave) connections, two switches are required for
distances greater than 10 km (6.2 miles). Distances up to 30 km (18.6 miles) are supported. Long-distance
solutions are provided, based on user requirements and workload characteristics, using approved channel
extenders and communication lines (for example, T1/T3/ATM).
The MCU-to-RCU remote copy configuration for TC390A has different requirements than the TC390
Synchronous configuration:
• TC390 Synchronous supports 1-to-n and n-to-1 remote copy connections (n4). One MCU can be
connected to as many as four RCUs, and one RCU can be connected to as many as four MCUs (one
MCU/RCU = one physical CU, including all CU images). TC390 supports the dynamic switching
capability of the ESCDs that is used to share the physical interface cables between the components.
The ESCDs can accommodate channel-to-MCU and channel-to-RCU connections in addition to the
remote copy connections
• TC390A supports 1-to-1 remote copy connections within the same consistency group. The M-VOLs and
R-VOLs of the pairs in a consistency group must be located within one physical MCU and one physical
RCU. This configuration ensures backup integrity for data which is spread across multiple volumes
within one disk array.
XP Continuous Access 1-to-n and n-to-1 configurations are valid for TC390A, as long as each
consistency group does not span local or remote disk arrays.
• Fibre remote copy supports 1-to-1 remote copy connections. One disk array as an MCU can be
connected to only one disk array as an RCU via optical fibre cables. For the CU images within one disk
array, 1-to-4 and 4-to-1 remote copy connections are supported.
NOTE: HP strongly recommends that you establish at least two independent remote copy
connections (one per cluster) between each MCU and RCU to provide hardware redundancy for
this critical communications path.
• One MCU port (initiator port) can be connected to 64 RCU ports (RCU target ports). One RCU port
can be connected to 16 MCU ports. However, the number of logical paths that can be specified does
not depend on the number of connectable RCU or MCU ports.
For disk arrays with both TC390 and FICON host attachment, you must set the path configuration carefully.
The following table lists the possible path configurations and indicates which combinations are supported.
Table 4 TC390 configuration with FICON
Application Site Path (System - DKC) MCU-RCU For Use
ESCON ESCON Not Supported
ESCON Fibre Channel Supported