Functional and Operational Characteristics  3-11 
Hitachi Universal Storage Platform V/VM User and Reference Guide 
Mode  Category  Function  Default  MCU/RCU 
64 
(cont.) 
TrueCopy for z/OS  Mode 64 = OFF (default): 
  When receiving the Freeze command, pairs that fulfill the 
conditions below are suspended and the SCP is set. In the 
case of CU emulation type 2105/2017, the path between 
MCU and RCU is deleted, while the path is not deleted but 
unusable with Query displayed only in the case of CU 
emulation type 3990.  
  When receiving the RUN command, the SCP status of the 
pairs that fulfill the conditions below is released. 
  When a Failure Suspend occurs while the Freeze Option 
Enable is set, except the pair in which the Failure Suspend 
occurs, other pairs that fulfill the conditions below go into 
SCP state. 
Conditions:  
  TrueCopy Sync M-VOL 
  Mainframe Volume 
  Pair status: Duplex/Pending 
  A pair whose RCU# is identical to the RCU for which the 
Freeze command is specified. 
Note: 
1.  General use: Mode 64=Off (default) 
2.  When all the following conditions are met, set Mode 
64=ON. 
  Customer requests to stop the update I/O operation to 
the RCU of a TrueCopy for z/OS pair for the whole 
subsystem. 
  Disaster Recovery function such as GDPS, HyperSwap, 
or Fail Over/ Fail Back, which requires compatibility with 
IBM storage, is not used as this Mode 64 operates 
without having compatibility with IBM storage. 
  Only Peer-to-Peer-Remote-Copy operation. (Do not use 
it in combination with Business Continuity Manager.) 
3.  Even though the Failover command is not an applicable 
criterion, when executing the Failover command while 
Mode 114 is ON, since ports are not automatically 
switched, the Failover command fails. 
4.  With increase of Sync pairs in subsystem, the time period 
to report the completion of Freeze command and RUN 
command gets longer (estimate of time to report 
completion: 1 second per 1000 pairs), and MIH may occur. 
OFF MCU/RCU 
80 
ShadowImage for 
z/OS 
Determines whether Quick Restore or Reverse Copy, if not 
specified, is performed at the execution of pairresync by CCI. 
Mode 80 = ON: Reverse Copy is performed. 
Mode 80 = OFF: Quick Restore is performed. 
OFF – 
87 ShadowImage 
Determines whether NormalCopy or QuickResync, if not 
specified, is performed at the execution of pairresync by CCI. 
Mode 87 = ON: QuickResync is performed. 
Mode 87 = OFF: NormalCopy is performed. 
OFF – 
93 
TrueCopy for z/OS 
Async 
TrueCopy for z/OS Async throttling feature.  OFF  MCU 
104  TrueCopy for z/OS  Changing default of CGROUP Freeze option.  OFF  MCU