HP StorageWorks XP Remote Web Console Software - Manual (Page 15)

Read Option” (page 21) allows read-only access to a TrueCopy for Mainframe R-VOL while the
pair is suspended.
TrueCopy for Mainframe supports a maximum of 32,768 pairs (entire XP24000/XP20000 RCU).
If the command device for Business Continuity Manager is defined, the TrueCopy for Mainframe
pair can be created up to 32,767 pairs. TrueCopy for Mainframe supports the basic logical volume
images (LVIs) available on the HP disk array (for example, 3390-3, 3390-3R, 3390-9).
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
CAUTION: If you connect the IBM OS installed host and the Fujitsu OS installed host to the same
storage system, call HP technical support when creating TrueCopy for Mainframe or TrueCopy for
Mainframe Asynchronous pairs by using volumes that are connected by the IBM OS installed host.
Remote Copy Connections
The remote copy connections are the physical paths used by the TrueCopy for Mainframe MCUs
to communicate with the TrueCopy for Mainframe RCUs. The maximum number of physical paths
per logical CU is eight for Fibre Channel. The MCUs and RCUs are connected via Fibre Channel
interface cables.
When Fibre Channel interface (single-mode longwave) 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. 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 TrueCopy for Mainframe Asynchronous has different
requirements than the TrueCopy for Mainframe Synchronous configuration, as follows:
•
TrueCopy for Mainframe Sync 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 CUs). TrueCopy for
Mainframe supports the dynamic switching capability of the ESCDs which 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.
NOTE: TrueCopy 1-to-n and n-to-1 configurations are only valid if BCM is not used.
•
TrueCopy for Mainframe Async 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 HP disk array (for example, large
databases).
TrueCopy for Mainframe 1-to-n and n-to-1 configurations are valid for TrueCopy for Mainframe
Async, as long as each consistency group does not span local or remote storage systems.
•
Fibre remote copy supports 1-to-1 remote copy connections. One HP disk array as an MCU
can be connected to only one HP disk array as an RCU via optical fibre cables. For the CUs
within one XP disk array, 1-to-4 and 4-to-1 remote copy connections are supported.
•
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.
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.
TrueCopy for Mainframe Components 15