IBM would prefer to sell its own DS or XIV series of disk arrays to its System z mainframe customers, but mainframe shops sometimes have other ideas, such as buying Symmetrix DMX or VMAX arrays. And that's why Big Blue has extended an interoperability and technology licensing agreement with disk array rival EMC.
Under the multi-year agreement, IBM is giving EMC access to the APIs in the current and future releases of its System z operating systems, which include the flagship z/OS, the z/VM operating system (which also functions as a hypervisor on some configurations), the z/TPF transaction processing system used by reservation systems, and the z/VSE baby mainframe operating system that probably doesn't see a lot of EMC action.
There is also, of course, Linux from Red Hat and Novell available to run in z/VM logical partitions, too, that needs to be able to reach out and talk to EMC disk arrays.
The agreement allows various storage software features on the System z platform, including Peer-to-Peer Remote Copy (PPRC) and Extended Remote Copy (XRC) functions as well as FlashCopy, Multiple Allegiance, Parallel Access Volumes (PAV), Dynamic PAV, and HyperPAV.
IBM and EMC sat down and inked their first cross-licensing agreement for mainframes back in October 2003, with IBM providing EMC with a range of mainframe and other storage interfaces; the two companies also agreed to cooperate on open interfaces evolving in the storage arena at the time. In June 2005, EMC and IBM inked a cooperative support agreement that integrates the tech support teams of both companies so they can coordinate support responses to customers mixing IBM mainframe, Power, and x64 systems. This agreement is still in effect today.
In March 2006, EMC and IBM inked a formal deal specifically for the storage interfaces in its OS/400, i5/OS, and IBM i proprietary midrange platforms, allowing EMC's Symmetrix DMX arrays to work with i5/OS V5R4 and future releases. This technology swap was renewed in May 2010. The mainframe storage interface agreement was last renewed in June 2007.
Financial terms of the technology exchanges between EMC and IBM have never been divulged in the past, and the terms were not announced this time, either.
IBM and EMC fought very hard over the mainframe disk business in the late 1980s and early 1990s, and EMC had far better technology for many years. As the companies found their new equilibrium market shares for disk capacity in the IBM mainframe and AS/400 markets as the 1990s came to a close, that was also when the 1956 antitrust decree that IBM signed with the US government was getting ready to expire.
Among many other things, that consent decree, which settled a 1952 lawsuit that predates the modern computer age but which governed IBM's behavior in computing just the same, compelled IBM to support machines that had third party devices, such as disk drives and main memory, installed on them and to provide interfaces to machines to third parties so they could create such devices. So if IBM didn't play nice with EMC, Hitachi Data Systems, and other suppliers, a whole lot of lawyers could be unleashed by third party disk suppliers that were shut out.
IBM wriggled out of the consent decree in January 1996, and the portions of the agreement between Uncle Sam and Big Blue relating to the mainframe expired in July 2000 and for the AS/400 in July 2001. IBM does not, in fact, have to provide EMC with jack. But IBM has learned that sharing and competing is just easier and smarter. ®