HP XP P9500 Storage - Manual (Page 9)

Main (MCU), remote (RCU) disk arrays
The main disk array manages the M-VOL and the following operations:
•
Host I/O operations to the M-VOL
•
Initial copy and update copy operations between the M-VOL and R-VOL.
•
Pair status and configuration information
The remote disk array manages the R-VOL and the following operations:
•
Remote copy operations issued by the main system
•
Assists in managing pair status and configuration (for example, rejects write I/Os to the R-VOL).
The P9500 CU can function simultaneously as a main disk array for one or more M-VOLs, and as
a remote disk array for one or more R-VOLs. This kind of configuration requires that data paths
and Fibre Channel ports to be properly configured for both copy directions.
When you use XP12000 Disk Array/XP10000 Disk Array for MCU or RCU, the CU number that
can be used is limited. The following table provides the CU number range when P9500,
XP24000/XP20000 Disk Array, or XP12000 Disk Array/XP10000 Disk Array is used for MCU
or RCU.
Table 1 CU number range when P9500, XP24000/XP20000 Disk Array, or XP12000 Disk
Array/XP10000 Disk Array is used for MCU or RCU
RCU MCU
P9500 XP24000/XP20000 Disk
Array XP12000 Disk
Array/XP10000 Disk Array
MCU:0x00 to 0x3f MCU:0x00 to 0x3f MCU:0x00 to 0x3f XP12000 Disk
Array/XP10000 Disk Array
RCU:0x00 to 0x3f RCU:0x00 to 0x3f RCU:0x00 to 0x3f
MCU:0x00 to 0xfe MCU:0x00 to 0xfe MCU:0x00 to 0x3f XP24000/XP20000 Disk
Array
RCU:0x00 to 0xfe RCU:0x00 to 0xfe RCU:0x00 to 0x3f
MCU:0x00 to 0xfe MCU:0x00 to 0xfe MCU:0x00 to 0x3f P9500
RCU:0x00 to 0xfe RCU:0x00 to 0xfe RCU:0x00 to 0x3f
IMPORTANT: If you are creating a Continuous Access Synchronous Z pair with different series
of disk arrays (for example, P9500 and XP12000 Disk Array/XP10000 Disk Array), make sure
that each disk array has a unique serial number. It is possible that a serial number overlap could
occur (although this would be extremely rare). If you have two disk arrays with the same serial
number and you need to configure remote copy pairs between the two storage systems, contact
your HP account team for assistance.
Volume pairs
As described above, data written from the mainframe host is stored in the M-VOL and the remote
copy is stored in the R-VOL. The pair can be suspended, resynchronized, reverse resynchronized,
and returned to the Simplex state.
•
When paired, the volumes are synchronized.
•
When suspended, new data is sent to the M-VOL but not the R-VOL.
•
When resynchronized, changed data is copied to the R-VOL.
•
When necessary, data in the R-VOL can be copied to the M-VOL.
During normal operations, the M-VOL remains available to the host for read and write I/O
operations. The remote system rejects write I/Os for the R-VOL, unless the write-enable option is
Volume pairs 9