IBM 890 GDPS/PPRC and GDPS/XRC FlashCopy Support, GDPS/PPRC Multiplatform Resiliency for zSeries

GDPS/PPRC and GDPS/XRC FlashCopy Support

FlashCopy is a point-in-time copy technology that allows point-in-time copies of disk volumes to be made very quickly, with the copies immediately available for read or write access. FlashCopy can operate in either of two modes, the COPY mode which runs a background copy process and the NOCOPY mode that suppresses the background copy. Previously GDPS/PPRC and GDPS/XRC have provided support for both COPY and NOCOPY. With the release of GDPS/PPRC V3.2 and GDPS/XRC V3.2,

an enhancement now available, called NOCOPY2COPY, allows changing an existing FlashCopy relationship from NOCOPY to COPY. This allows you the option of always selecting the NOCOPY option of FlashCopy and then con- verting it to the COPY option when you want to create a full copy of the data in the background at a non-peak time.

Another enhancement now available with GDPS V3.2 is support for Incremental FlashCopy. This provides the capability to refresh a volume in a FlashCopy relationship and reduce background copy time when only a subset of data has changed. With Incremental FlashCopy, the initial relationship between a source and target is main- tained after the background copy is complete. When a subsequent FlashCopy establish is initiated, only the data updated on the source since the last FlashCopy is copied to the target. This reduces the time needed to create a tertiary copy thus giving customers the option to perform a FlashCopy on a more frequent basis.

In 2003, IBM TotalStorage Enterprise Storage Server announced support of FlashCopy V2. Refer to Hardware Announcement 103-141, dated May 13, 2003. Prior to this announcement, both source and target volumes had to reside on the same LSS within the disk subsystem. Since this constraint has been removed with FlashCopy V2, GDPS can now allow a FlashCopy from a source in one

LSS to a target in a different LSS within the same disk sub- system. This new fl exibility can help simplify administration and capacity planning for FlashCopy.

GDPS/PPRC Multiplatform Resiliency for zSeries

GDPS/PPRC has been enhanced to include a new func- tion: GDPS/PPRC Multiplatform Resiliency for zSeries.

This function is especially valuable for customers who share data and storage subsystems between z/OS and Linux on zSeries – for example, a SAP application server running on Linux on zSeries and a SAP DB server running on z/OS. With a multi-tiered architecture, there is a need to provide a coordinated Disaster Recovery solution for both z/OS and Linux on zSeries. GDPS/PPRC can now provide that.

z/VM 5.1 provides a new HyperSwap function so that the virtual device associated with one real disk can be swapped transparently to another. HyperSwap can be used to switch to secondary disk storage subsystems mir- rored by Peer-to-Peer Remote Copy (PPRC). HyperSwap can also be helpful in data migration scenarios to allow applications to use new disk volumes without requiring them to be quiesced.

GDPS/PPRC can provide the reconfi guration capabili- ties for the Linux on zSeries servers and data in the same manner as for z/OS systems and data. To support planned and unplanned outages, GDPS is designed to provide the following recovery actions:

•Re-IPL in place of failing operating system images

•Site takeover/failover of a complete production site

•Coordinated planned and unplanned HyperSwap of storage subsystems transparently to the operating system images and applications using the storage

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