HP StorageWorks XP Remote Web Console Software User Manual
Page 129
Hitachi TrueCopy for z/OS user guide 129
NOTE:
When you create a TC390 pair, and if you select only M-VOL for the CFW data option, the
data set which is updated by CFW in M-VOL cannot be used in R-VOL. To use this data set in R-VOL,
delete a TC390 pair, and format the data set.
NOTE:
If a TC390 pair is established using PPRC commands, the CFW data option is set to the
Copy to R-VOL setting.
NOTE:
By using Remote Copy Function Switch, you can set the following option with CESTPAIR:
CFW data = only M-VOL. To use this function, please contact your HP account support
representative.
• The DFW to R-VOL option (TC390 Synchronous only) specifies whether the MCU will suspend a
TC390 volume pair when the RCU cannot execute DFW to the R-VOL:
If DFW not required is selected, the MCU will not suspend the TC390 volume pair when DFW on
the RCU is blocked. This option is recommended if you need to maintain synchronization of the
TC390 volume pair.
NOTE:
If a TC390 pair is established using PPRC commands, the DFW to R-VOL option is set to
not required.
If DFW required is selected, the MCU will suspend the pair when DFW on the RCU is blocked. This
option is recommended if you need to maintain high MCU I/O performance.
CAUTION:
The interaction of the DFW required setting and the M-VOL fence level setting can
cause a host application to fail with a permanent I/O error when attempting to update an M-VOL.
Keep track of which volume pairs have the DFW required setting and verify that DFW to the R-VOL
is not blocked.
NOTE:
The DFW to R-VOL setting does not affect the I/O performance of the M-VOLs. If one side
of cache is closed due to an RCU failure, the TC390 copy operation still uses DFW. The only
difference between not required and required is that new pairs cannot be established with the
DFW-to-R-VOL required option when one side of RCU cache is closed (the add pair operation fails).
•
Asynchronous Parameters: Can be selected only for the Asynchronous pair(s).
• CT Group: C/T Group. This option specifies the consistency group for the pair(s) being added
(TC390A only). All TC390A pairs must be assigned to a consistency group.
NOTE:
Only TCzA pairs belonging to the same CLPR can be allocated to one consistency group.
For more information about CLPRs, see the XP Command View Advanced Edition Software online
help or the HP StorageWorks XP Remote Web Console User Guide for the specific disk array.
NOTE:
The CESTPAIR command can be used to start TC390A pairs and assign them to groups,
but the groups must already be configured (using the Add C/T Group window, see ”
consistency groups (Add CT Group)
• The Error Level (Async) option (TC390A only) specifies the error level for the TC390A pair(s):