Sunday, July 20, 2008

zIIP Assisted z/OS Global Mirror: Significant cost reduction

Going back through some of the more recent processor announcements reminded me there are some significant cost savings available to the hundreds of XRC (Global Mirror for zSeries) customers out there.

Global Mirror for zSeries is of course, an asynchronous disk mirroring technique that mirrors mainframe data across any distance. This process is controlled by the SDM (or System Data Mover) which is application code running in one or more z/OS LPARs – usually at the recovery site.

Depending upon the size of the configuration – the number of volumes to be mirrored and the number of XRC “readers” defined, this could place a significant load on the processor CPs, and could require multiple CPs just to support the SDMs.

Beginning with z/OS 1.8, IBM began enabling much of the SDM code to be eligible to run on the IBM System z9 and z10 Integrated Information Processors (zIIPs). The zIIP assisted z/OS Global Mirror functions can provide better price performance and improved utilization of resources at the mirrored site.

This improved TCO (Total Cost of Ownership) is accomplished in two ways: First, IBM charges less for the specialty processors – like zIIPs – than then standard general purpose CPs. Secondly, the processing power used on zIIP processors enabled on the physical z9 or z10 CEC is NOT included in the general MSU ("Millions of Service Units”) figure that vendors use to determine your software charges.

Thus, if you are not currently offloading the SDM processing onto the zIIP processors on your z9 or z10, then you could experience some significant cost savings by moving towards this configuration.

No comments: