Volume pairs (m-vols and r-vols), Remote copy connections – HP StorageWorks XP Remote Web Console Software User Manual
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Changing from 3990 to 2105: If you need to change the emulation from 3990 to 2105 for an
XP128/XP1024/XP10000/XP12000 that has existing HXRC pairs, you must:
1.
Stop all jobs and delete all HXRC pairs.
2.
Change the CU emulation type of all CHA packages in the XP128/XP1024/XP10000/XP12000 to
2105. Do not intermix 3990 and 2105 emulations in the same disk array.
3.
Restart jobs and re-establish HXRC pairs.
NOTE:
The PPRC commands are different for 3990 and 2105 emulation types. For more information on
using PPRC TSO commands with 2105 emulation, refer to ”
Using PPRC Commands for TrueCopy
NOTE:
For important information on GDPS support and 2105 emulation, see ”
Volume Pairs (M-VOLs and R-VOLs)
TC390 performs remote copy operations for logical volume pairs established by the user. Each TC390 pair
consists of one main volume (M-VOL) and one remote volume (R-VOL), which are located in different disk
arrays. The TC390 M-VOLs are the primary volumes that contain the original data, and the TC390 R-VOLs
are the secondary or mirrored volumes that contain the backup or duplicate data. The main and remote
volumes must have the same format and capacity.
During normal TC390 operations, the TC390 M-VOL remains available to all hosts at all times for read
and write I/O operations. The RCU rejects all I/Os to a TC390 R-VOL. The R-VOL read option (see ”
” on page 28) allows read-only access to a TC390 R-VOL while the pair is suspended.
TC390 supports a maximum of 8192 pairs. TC390 supports the basic logical volume images (LVIs)
available on the XP128/XP1024/XP10000/XP12000, such as 3390-3, 3390-3R, 3390-9, and 3390-L.
For information on LVI requirements and support, see ”
CAUTION:
Do not use M-VOLs or R-VOLs from hosts that have different CU emulation types (2105 and
3990) at the same time. If you use the M-VOLs or R-VOLs from the 2105 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