IBM has announced its TotalStorage SVC (SAN Volume Controller) will now support Cisco's MDS 9000 family of switches. At the end of April, it announced support for EMC's Symmetrix and Clariion disk arrays.

So TotalStorage SVC will now be capable of managing storage on IBM systems, as well as EMC's Clariion, Hitachi Data Systems' Thunder and Lightning, and HP's EMA and MA systems.

Using the system, IT managers can administer applications such as volume management and data replication and make point-in-time copies directly from the network. IBM plans to add support for EMC's DMX and HP's EVA in the near future.

IBM also announced support for iSCSI (Internet SCSI) connectivity for low-cost environments. Previously, the product only supported devices that use the more expensive Fibre Channel protocol.

Although the announcement is a big move for IBM, it is not the final word on storage virtualisation - an approach which purports to make management easier and allow IT departments to use various types of storage depending on the importance of the data being stored. It is a concept that has proved easier to discuss than to implement. "It has been difficult to carry out effectively but we're starting to see products that are beginning to deliver on the promise of virtualisation," said Mike Kahn, an analyst at the Clipper Group.

EMC officials believe that customers do not want a separate device to manage their storage, such as the one IBM offers. Instead, it says, customers want to integrate storage virtualisation with products they currently have, particularly products from switch vendors such as Brocade, Cisco and McData. "We believe customers want to manage their storage from products they already have, not by adding another black box, which is essentially what IBM is doing," said Chuck Hollis, vice president of storage platform marketing at EMC.

EMC plans to combine storage virtualisation with server virtualisation in the future - part of the strategy behind EMC's purchase of VMware earlier this year. VMware's software allows multiple operating systems to run simultaneously on the same Intel-based server, allowing users to shift applications from server to server as corporate needs change.

Brocade has already announced its SilkWork Fabric Application Platform, which allows Brocade, as well as ISVs, to write applications for volume management, data migration, and data replication over multiple SANs and multiple networks. EMC, HP, and Veritas Software have said they plan to develop applications for Brocade's platform. Products supporting SilkWorm are expected to arrive shortly, according to Brocade officials.

IBM, however, believes its latest product is giving a shot in the arm to the virtualisation concept and can be used immediately by IT departments. "It can be a real cost and time-saver for IT departments by pooling storage, adding availability and simplifying management," said Jeff Barnett, manager of storage software strategy at IBM.

One early user of the TotalStorage SVC said he has seen beneficial changes using the virtualisation model. "We are able to make the shift today from managing storage on different servers to a switch-based vendor-independent management model," said Claus Kalle, manager of the systems department at the University of Cologne in Germany.

"There is going to be more than one choice for IT departments in the near future," Clipper Group's Kahn said. "We're just seeing the beginnings of storage virtualisation."