HP XP P9000 Continuous Access Synchronous for Mainframe Systems User Guide

12. In the Minimum Paths box, enter the minimum number of paths necessary for operations to
continue. If the number of paths in Normal status falls below the Minimum Paths value you
set, the main system suspends Cnt Ac-S Z pairs. This is done to prevent a performance drop
on the host because of low overall bandwidth between main and remote system. The default
is 1.
• If your pairs contain critical data and you are using Cnt Ac-S Z for disaster recovery, set
the minimum number to one. This ensures that Cnt Ac-S Z operations continue even when
there is only one remaining data path.
• If performance is a higher priority than maintaining critical data, set the minimum number
of paths to two or more (up to eight per CU).
NOTE: If the pair is suspended because the number of paths has dropped below the Minimum
Paths setting, the P-VOL fence level determines whether write operations continue or are rejected
to the P-VOL.
13. In the RIO MIH Time (sec.) (Remote I/O Missing Interrupt Handler Time) box, enter the amount
of time that can pass before the system stops the copy operation as failed. The range of time
is from 10 seconds to 100 seconds. The default is 15 seconds.
14. Use FREEZE to enable or disable support for the CGROUP (FREEZE/ RUN) PPRC TSO
command. FREEZE is available only when PPRC support by host = Yes.
• If you select Enable, the main system will accept and perform the CGROUP command.
• If you select Disable, the main system will reject the CGROUP command.
Enable FREEZE only after all main-remote paths have been added.
The PPRC commands do not allow you to change the remote system options.
15. In the Round Trip Time (ms) box, set a time limit in milliseconds for data to travel from the
P-VOL to the S-VOL. This value is used by the system to control initial copy pace when update
copying is in progress.
Configuring storage systems, defining logical paths 61