IBM z/OS - Manual (Page 41)

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unplanned HyperSwap capability lays the foundation for
continuous availability, even in the event of a complete
site failure. In the event of a complete failure of the site
where the primary disk resides, the systems in the site with
the secondary disks can continue to remain active even
though workload running on these systems needs to be
restarted. An improvement in the Recovery Time Objective
(RTO) can be accomplished.
Geographically Dispersed Parallel Sysplex (GDPS)
enhancements
GDPS, an world-class e-business continuity solution, is a
multisite solution that is designed to provide the capabil-
ity to manage the remote copy confi guration and storage
subsystems, automate Parallel Sysplex operational tasks,
and perform failure recovery from a single point of control,
thereby helping to improve application availability. GDPS
supports both the synchronous Peer-to-Peer Remote Copy
(PPRC), as well as the asynchronous Extended Remote
Copy (XRC) forms of remote copy. Depending on the form
of remote copy, the solution is referred to as GDPS/PPRC
or GDPS/XRC.
GDPS/PPRC and GDPS/XRC have been enhanced to
include new functions.
GDPS/PPRC HyperSwap function: The GDPS/PPRC
HyperSwap function is designed to broaden the continu-
ous availability attributes of GDPS/PPRC by extending the
Parallel Sysplex redundancy to disk subsystems.
Planned HyperSwap function provides the ability to:
• Transparently switch all primary PPRC disk subsystems
with the secondary PPRC disk subsystems for a planned
reconfi guration
• Perform disk confi guration maintenance and planned
site maintenance without requiring any applications to
be quiesced.
Planned HyperSwap function became generally available
December 2002.
Unplanned HyperSwap function contains additional func-
tion to transparently switch to use secondary PPRC disk
subsystems in the event of unplanned outages of the
primary PPRC disk subsystems or a failure of the site con-
taining the primary PPRC disk subsystems. Unplanned
HyperSwap support can allow:
• Production systems to remain active during a disk sub-
system failure. Disk subsystem failures will no longer
constitute a single point of failure for an entire Parallel
Sysplex.
• Production servers to remain active during a failure of
the site containing the primary PPRC disk subsystems
if applications are cloned and exploiting data sharing
across the two sites. Even though the workload in the
second site will need to be restarted, an improvement
in the Recovery Time Objective (RTO) will be accom-
plished.
Unplanned HyperSwap function became generally avail-
able February 2004.