DS8000 HyperSwap with independent auxiliary storage pools (IASPs) is now supported within the Enterprise Edition of IBM PowerHA SystemMirror for i. IASP based HyperSwap is the next stage in DS8000 HyperSwap support on IBM i and provides near-zero downtime for planned and unplanned storage outages. It can be used in conjunction with other IASP-based PowerHA technologies and is available via 7.2 PowerHA PTFs with both release 7.2 and 7.3 of IBM i.

HyperSwap is a System Storage function which allows an application to switch between two storage servers with essentially zero downtime, using Metro Mirror to synchronize the data between the storage servers.

Prior to this announcement, the 7.2 IBM PowerHA SystemMirror for i product included support for full system DS8000 HyperSwap as part of the Express Edition of PowerHA. This allowed the system administrator to manage the HyperSwap environment from IBM I, and initiate a switch between the storage servers. It also allowed the definition of affinity between a POWER server and a DS8000 storage server, so that if a live partition mobility switch was initiated to move an IBM I partition to a different POWER server, the logical units (LUNs) associated with the partition would also move to the DS8000 server with defined affinity to the new POWER server. Full system HyperSwap is not compatible with IASP-based replication, and can only be configured at the system level (all of SYSBAS and any defined IASPs would all switch together). This is because the HyperSwap relationship was defined at the system level, and not at the ASP group level.

Now, PowerHA Enterprise Edition will support DS8000 HyperSwap at an IASP level. The HyperSwap relationship can be defined on an ASP within the partition, allowing SYSBAS and the IASPs to be in separate HyperSwap relationships. This is necessary because for a truly resilient environment, SYSBAS may be replicated in a different direction that the IASP.

With this support, HyperSwap can be used for near zero downtime in the event of a planned or unplanned storage outage, and can be combined with PowerHA LUN switching technology to provide a minimal downtime solution for planned and unplanned server outages.

Prerequisites for this technology include:

A system utilizing independent auxiliary storage pools for data replication, running IBM i 7.2 TR4 or IBM i 7.3 and IBM PowerHA SystemMirror for i Enterprise Edition 7.2
A second partition either already configured as the target node in a PowerHA switched LUN configuration or available to be configured
Two DS8800 (or above) storage servers