The Continuous Access Synchronous Consistency Preservation Function - HP XP P9500 Software User's Manual

4. Reverse the copy direction again using the Reverse Resync function.
To return the copy direction back to the original direction, execute the YKSUSPND and
YKRESYNC command with the FORWARD parameter specified for both.
5. Start all applications at the primary site.
Figure 42 Flow of Failovers and Failbacks

The Continuous Access Synchronous Consistency Preservation Function

Continuous Access Synchronous for Mainframe provides storage system functionality that preserves
the consistency of the volume update sequence for each copy pair, even if a failure occurs on a
volume or line. This function is called the Continuous Access Synchronous consistency preservation
function.
The Continuous Access Synchronous consistency preservation function preserves the consistency
of all copy pairs within a Continuous Access Synchronous for Mainframe copy group that has a
consistency group ID specified. By preserving the consistency among multiple copy pairs within a
copy group, the files within copy groups on the S-VOL side can maintain the status immediately
preceding a failure (or during a planned outage).
NOTE: For a Continuous Access Synchronous for Mainframe copy group without a consistency
group ID specified, the storage system preserves the consistency for each copy pair only.
To set up the Continuous Access Synchronous Consistency Preservation Function, see
definition for using the Continuous Access Synchronous Consistency Preservation function" (page
To preserve Continuous Access Synchronous for Mainframe consistency, execute a script containing
the YKCONMSG, YKFREEZE, YKSUSPND and YKRUN commands as follows:
78 Understanding Business Continuity Manager functions
"Configuration
123).