Hitachi Virtual Storage Platform, User And Reference Manual

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Hitachi VSP User and Reference Guide
2–40
Functional and Operational Characteristics
784
1 of 2 TrueCopy
TrueCopy for
Mainframe This mode can reduce the MIH watch time of RI/O
for a TrueCopy for MainframeS or Continuous
Access Synchronous pair internally so that update I/
Os can continue by using an alternate path without
MIH or time-out occurrence in the environment
where Mainframe host MIH is set to 15 seconds, or
Open host time-out time is short (15 seconds or
less). The mode is effective at initial pair creation or
Resync operation for Hitachi TrueCopy®
Synchronous software for Mainframe or Continuous
Access Synchronous. (Not effective by just setting
this mode to ON)
Mode 784 = OFF (default):
The operation is processed in accordance with the
TC Sync for z/OS or TC Sync specification.
Special Direction
• (1)The mode is applied to the environment
where Mainframe host MIH time is set to 15
seconds.
• (2)The mode is applied to the environment
where OPEN host time-out time is set to 15
seconds or less.
• (3)The mode is applied to reduce RI/O MIH
time to 5 seconds.
• (4)The mode is effective for the entire system.
Notes:
1. This function is available for all the TC Sync for
z/OS and TC Sync pairs on the subsystem,
unable to specify the pairs that are using this
function or not.
2. RAID700) To apply the mode to TC Sync, both
MCU and RCU must be RAID700 and micro-
program must be the support version on both
sides. If either one of MCU or RCU is RAID600,
the function cannot be applied.
3. For a TC Sync for z/OS or TC Sync pair with the
mode effective (RI/O MIH time is 5 seconds),
the setting of RI/O MIH time made at RCU
registration (default is 15 seconds, which can
be changed within range from 10 to 100
seconds) is invalid. However, RI/O MIH time
displayed on Storage Navigator and CCI is not
"5 seconds" but is what set at RI/O registration.
4. To apply the mode to TC Sync for z/OS, MCU
and RCU must be RAID600 or RAID700 and
micro-program must be the support version on
both sides.
5. If a failure occurs on the switched path between
DKCs, Mainframe host MIH or Open server
time-out may occur.
(Continued below)
OFF MCU/RCU
Mode Category Description Default MCU/RCU