IBM z/OS - page 41

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.