IBM, Hitachi Take Storage Interoperability To API Level

IBM and Hitachi Data Systems, which earlier this week revealed participation with four other storage vendors in an initiative to provide cross-vendor storage network interoperability, on Wednesday took interoperability one step further with an agreement to license a number of each others' APIs.

IBM is licensing the APIs for its Peer-to-Peer Remote Copy (PPRC), Extended Remote Copy (XRC) FlashCopy, Multiple Allegiance, and Parallel Access Volumes (PAV) from its Shark Enterprise Storage Server to Hitachi to use on its Lightning 9900 storage arrays.

Hitachi, for its part, is licensing the APIs for the NanoCopy and ShadowImage functions of its 9900 to IBM to use on the Shark.

XRC, PAV and Multiple Allegiance are aimed at the OS/390 space, while PPRC and FlashCopy work on open systems.

The API licensing agreement is another example of a push for interoperability at the functional level, says Mike Harrison, director of business alliances for IBM Storage.

"For clients with Shark and Hitachi [arrays] on the same network, they can now run disaster recovery applications and backup procedures, and improve performance, across both platforms," Harrison says.

Functions such as PPRC and XRC are typically proprietary to a single storage environment, which means a customer with a Shark storage system can't use them with a 9900 on the same SAN, Harrison says. However, with 6,300 Sharks installed worldwide and sales of the 9900 picking up, there is an increasing chance the two will be found in the same data center, he says.

Once the Shark and 9900 have common APIs, clients who learn one vendor's management tools will not have to learn new tools if the other vendor's array is installed, says Claus Mikkelsen, director of storage applications at Hitachi. "Trying to learn a second product is like learning to drive on the left side of the road if you are used to driving on the right side," he says.

With the common APIs, clients will no longer be tied to a single vendor's array, but can instead choose whichever is best for their needs, Mikkelsen says. "Clients can have an IBM and Hitachi box side by side, or in separate locations," he says. "They can put half a DB2 [database] file on a Shark and the other half on a 9900, and they will work seamlessly."

Even though the licensing agreement has been signed, there will be some time before it affects the Shark and 9900.

It will require two to three months before the microcode patches are available to allow one vendor's array to use the other's APIs. However, once the microcode is in place, it will apply to both new and legacy Sharks and 9900s, Harrison says.

Several years ago, Hitachi acquired a license from IBM to support PPRC and XRC functions on its arrays, but the two comanies developed the functions independently, resulting in a divergence of features, Mikkelsen says. "This agreement brings us back in sync [with these two functions]," he says.

This is not IBM's first foray into interoperability agreements.

IBM and Compaq last year signed an agreement in which the two vendors certified that their storage products are interoperable. In addition, the agreement allows them to resell the other's storage products, Harrison says.

This new agreement is different in that the two vendors are licensing technology to each other, not OEMing each other's products, he says. "There's no reason to license our APIs to Compaq as part of that alliance because the APIs are already part of the product," he says. "So if you put a [Compaq Shark] and a 9900 on the same floor or connected them over some fabric, you would get the same interoperability."

Even though Hewlett-Packard OEMs the 9900 from Hitachi and sells it as the XP512 array, it is not yet clear whether the XP512 would have the same interoperability as the 9900, as HP adds its own value-add features.

Harrison says there is testing to do, but he is confident that with additional work the XP512 would fit in the same framework as the 9900. Mikkelsen agrees that testing is needed, but says the ShadowImage API is the same in both the XP512 and 9900.