Hitachi Extended Remote Copy for Mainframe user guide (HITA738-96004, June 2008)

NOTE:
When the DKC emulation type is 3990-6 or 3990-6E, only the XRC2 function is supported. When the DKC
emulation type is 2105 or 2107, XRC2 or XRC3 is supported.
The Number of Sessions
The following table shows the number of sessions in XRC for Mainframe.
Table 3 Number of XRC for Mainframe Session
Number of sessionsUnit
4,096Per disk subsystem
64Per CU
1Per logical volume
The number of Concurrent Copy (CC) and XRC for Mainframe sessions per logical volume depends
on the combination of CC and XRC (XRC2 and XRC3). The following table shows the number of
sessions per logical volume.
Table 4 Number of Sessions Per Logical Volume
DKU emulation type
3390-1, 3390-2, 3390-3, 3390-3R, 3390-9, 3390-L, 3390-MSession type
Number of XRC for Mainframe
sessions
Number of CC sessions
-16CC only
115CC and XRC2
115CC and XRC3
Considerations for Performance
Note the following when performing XRC for Mainframe operations.
• HP recommends that you have one ESCON path for one SC session.
• Take the block sizes into consideration when configuring the SC sessions (Do not issue too many
write I/Os with large block to one SC session).
• The performance of XRC for Mainframe is affected by the performance of SDM. Tune the SDM in
order to achieve the desired performance. For SDM tuning, see RedBooks Implementing ESS Copy
Services on S/390 published by IBM, or contact IBM.
Notes and Cautions
This section describes notes and cautions regarding XRC for Mainframe.
Hitachi Extended Remote Copy for Mainframe user guide 19