The Tagmastore is the latest version of Hitachi Ltd’s subsidiary HDS’ Lighting high-end disk array. Launched last fall, the most important quality of the box is that it sport virtualization software that allows it to pool the capacity of third-party disk arrays attached to it.
In November, Hitachi named IBM’s Shark ESS arrays as the first third-party box to be supported this way. Now it has added EMC’s Symmetrix arrays – both the DMX and older 3000, 5000 and 8000 series versions. Those are already on HDS’ support list. EMC’s mid-range Clariion arrays will be added at the end of January.
The TagmaStore eliminates the need for customers to buy expensive mirroring and snapshotting replication software to run on the third-party arrays. Instead they can use the Tagmastore’s replication software across all the arrays attached to it.
This is also true for a wide range of other vendors’ virtualization products, such as IBM’s SAN Volume Controller. EMC has very publicly said that it does not like this sort of virtualization, and for example has slammed the SVC as simply commoditizing array-based software. It puts forward technical arguments why replication is best completed on the array. These arguments are at least partly supported by analysts.
Recently, EMC responded to the news of the Symmetrix and Clariion qualification by saying: The problem is that the TagmaStore still requires customers to insert storage arrays between their servers and the Symmetrix or Clariion. That is an expensive and functionally limiting proposition.
EMC will launch its own virtualization system this year, but without threatening the company’s mirroring or snapshotting software sales. Its forthcoming Storage Router will only be able to move data for migration purposes and not for disaster protection between arrays – including even EMC’s own boxes.
