IBM Corp. and HItachi Data Systems Inc. (HDS) Thursday announced that they have signed joint licensing agreements to extend the interoperability and compatibility of their storage systems.

The companies also said they will collaborate on product interoperability testing to support Hitachi"s storage systems" compatibility with IBM"s zSeries mainframe. IBM has licensed its mainframe Ficon and Escon attachment specification for its high-end TotalStorage DS8000 Series and Shark storage array to Hitachi.

Under the agreement, Hitachi"s storage systems will support IBM"s mirroring and replication software, including Global and Metro data mirroring functions, z/OS Global Mirror, FlashCopy, parallel access volumes, as well as IBM"s Geographically Dispersed Parallel Sysplex clustering technology.

Charlie Andrews, director of IBM"s TotalStorage Solutions division, said the announcement goes well beyond earlier partnership agreements with any other storage vendor. "Instead of just exchanging hostages [intellectual property], we"ve agreed to work on interoperability and joint testing, so when customers integrate our technologies in their shops ... it will have been tested to validate that all the pieces work," Andrews said.

Claus Mikkelsen, senior director of storage applications at Santa Clara, Calif.-based HDS, said the deal is just the beginning of a new relationship between the two vendors that will include interoperability testing and an exchange of management code in future products. "It"s what customers want," Mikkelsen said.

"There are no time frames," he said. "There"s a lot of feature functions we"ll be working on together. The advantage is by doing this we can hasten the time frame of IBM releasing a function and Hitachi being able to interoperate with it. It just makes it easier all around."

Andrews wouldn"t disclose whether IBM is working to develop agreements with other vendors similar to the one with Hitachi.

"We have historically done intellectual property exchanges with more than just Hitachi. Our view is we"d like to promote openness and interoperability as best we can," he said. "Obviously, interoperability requires a common view on both sides. We believe we"ve reached that with Hitachi."