Virtualised SANs aren't just for large datacentres, claimed Hitachi Data Systems as it added a low-end model to its Universal Storage Platform (USP) series of dedicated storage controllers.

Called the USP-VM, the device can connect, virtualise and thin-provision storage from any vendor, said Bob Plumridge, product management director for HDS in Europe. He said that it replaces the NSC55, which did not support thin provisioning.

"This is a storage controller, built using proprietary Hitachi technology," he added. "We don't do virtualisation by putting servers in the data path, as IBM does with SVC for example. Our way is all self-contained and there is no need to alter the SAN."

The USP-VM can have Fibre Channel disks installed internally or heterogeneous multi-vendor storage attached to it externally. It can then provision that disk capacity as NAS, iSCSI, Fibre Channel, FICON or ESCON, or as a mix of those.

The rack-mounted device is built around switched 4Gbit/s Fibre Channel, and like its big brother, it can support up to 96PB of storage. As well as NAS, it can support tiered storage and virtual tape, and it runs on 220v, Hitachi said.

It can also virtualise the storage and apply thin provisioning so applications see a logical volume that's larger than it really is on disk. Only internal storage can be thin-provisioned for now, but Plumridge said the second release of microcode for the device - due this autumn - would add thin provisioning for external storage.

One of the target markets for the USP-VM is organisations which have been through consolidations and mergers, and now want to consolidate their multi-vendor storage without buying more capacity.

An administrator could for example attach an existing HP EVA disk system and put its unused capacity into the virtualised pool, he said, while leaving its data volumes unaltered.

The VM was developed because HDS had customers interested in its midrange USP-V line, but unable to afford the $150,000 entry-level price.

Plumridge acknowledged that, at about $60,000 (£30,000) for a diskless model, the VM could take business away from its bigger siblings, but added: "We would rather sell them a VM than nothing."

Instead, he said the VM gave customers a range to choose from, based on factors such as how many servers they have - "3000 is a clear-cut case for V, while 150 would be VM" - what applications they're running, and the IO throughput needed.

Also important are the customer's expectations for future growth, he said. That's because they use different hardware, so you cannot upgrade a VM to a V, although you could non-disruptively migrate storage from one to the other.