The use of ESS at the recovery site provides a unique ability to
combine FlashCopy® functions
with XRC functions. You can use this combination to create a consistent
copy of data for disaster recovery testing or point-in-time backup.
The following scenario describes a method of creating a usable
tertiary copy of data while keeping the existing data mover session
active:
- Suspend all volume pairs in the XRC session using the XSUSPEND
VOLUME(ALL) command.
- Issue FCESTABL commands to FlashCopy the
XRC secondary volumes to tertiary volumes within the same ESS. Do
not include volumes that contain the journal, state, control, and
master data sets.
- Use the DFSMDdss COPY DATASET command to FlashCopy XRC journal, state,
control, and master data sets to tertiary volumes within the same
ESS. Use the RENAMEUNCONDITIONAL parameter, specifying high level
qualifiers different from those in use by the currently active session.
Also specify the TOLERATE(ENQFAILURE) parameter.
- Once the FlashCopy relationships
are established, issue the XADDPAIR command with the SUSPENDED parameter
to begin resynchronization of the active session.
- Vary the secondary volumes (FlashCopy source
volumes) offline to the system on which the XRECOVER command will
be issued.
- Vary the tertiary volumes online to the system on which the XRECOVER
command will be issued.
- Issue the XRECOVER command with the HLQ and MHLQ
parameters specifying the new high level qualifiers used in step 3, and either the ONLINE or TERTIARY
parameter. The ONLINE or TERTIARY parameter indicates that it is permissible
to perform the recovery to volumes other than the original secondaries.
ONLINE indicates that any volumes matching the volsers of the original
secondaries may be used; TERTIARY specifies that the secondaries that
are used must not be the same as those that were in use when the XSUSPEND
was issued. The HLQ parameter is used to locate the XRC control,
state, and journal data sets. The MHLQ parameter is used to locate
the XRC master data set copied in step 3.
Note: The
XRECOVER command cannot run on the system that is currently running
the active session. Any attempt to do so will fail with a return code
416. The command may be issued on a different system running in the
same SYSPLEX.