Not surprisingly, EMC claims its virtualization features go beyond those of Hitachi’s, and HDS claims EMC is off base with those claims.

Brian Gallagher, EMC president of enterprise storage, made the case for EMC’s virtualization Monday during the opening of EMC World.

“We’ve extended Symmetrix’s data integrity to non-EMC devices. Hitachi does not do that,” Gallagher said. “Also, our technology is free of charge. You can virtualize any amount of non-EMC storage behind Symmetrix. Hitachi gives you a certain amount of terabytes for free, and then they charge when you go beyond that. Hitachi will also tell you not to use virtualization for databases, we don’t say that. We also extend FAST to other arrays. They [Hitachi] don’t extend auto tiering [to VSP].”

Claus Mikkelsen, chief scientist at HDS, disputed EMC’s points in an e-mail to Storage Soup. He said the HDS VSP supports “full inheritance” on externally virtualized storage devices from HDS or other vendors.

As for EMC’s free claim, Mikkelsen said “EMC states that software license enablement of FTS is a no-charge feature to customers, but fails to mention the future impact on software maintenance costs for the FTS license and any other EMC software license that charges maintenance based on installed capacity. With the Switch It On program from HDS, virtualization is free and third-party capacity is deeply discounted.”

Mikkelsen said HDS offers “prudent” advice on using virtualization with databases.

“We state that that Hitachi Dynamic Tiering on VSP will intelligently place data pages based on an application’s I/O access pattern,” he said. “Additionally, we recommend that customers do not immediately place OLTP database environments with high I/O transaction rates and low average response time requirements as externally virtualized storage. This is prudent advice that any intelligent storage vendor would recommend.”

Finally, Mikkelson said HDS’ technology does extend its Dynamic Tiering to third-party virtualized arrays.

EMC’s FTS will require time for users to kick the tires before it can be accurately judged, but the virtualization features are welcome additions.

“This is at least a step down the path to VSP-style virtualization,” said Ray Lucchesi, president of Silverton Consulting.

You can expect more steps – and more spats with HDS – before EMC’s array virtualization story is finished.