Hitachi Data Systems is adding software to its enterprise storage arrays that can find unused space on storage devices from multiple vendors and release it.

Hitachi's new technology, called Zero Page Reclaim, can examine all the capacity on a Hitachi disk array as well as third-party arrays attached to it over a SAN. An administrator can initiate Zero Page Reclaim without any disruption to the SAN, according to Hitachi. When the software finds unused blocks, it can return them to the pool of usable capacity.

Zero Page Reclaim is part of an update to the Hitachi Dynamic Provisioning software, this update also includes what the company calls automatic dynamic rebalancing. When a user adds physical disks, this feature automatically rebalances existing virtual volumes across those disks for maximum performance.

Hitachi's software resides on the company's own Universal Storage Platform disk arrays, but it can also control arrays from other vendors attached to the Hitachi gear. Effectively, Hitachi is allowing users to virtualise and manage all the storage capacity in a multi-vendor SAN, said John Harker, a Hitachi senior product marketing manager. The software can already provide replication, thin provisioning and disaster recovery on third-party arrays.

Hitachi Dynamic Provisioning has made it much easier for University HealthSystem Consortium to manage its storage, according to Don Naglich, director of technology infrastructure. UHC, a coordinating body for university medical centres across the US, has about 40 terabytes of storage capacity for all its applications. One of the organisation's jobs is to gather data from many medical centres and process it before sending it on to the US government.

UHC said it had reclaimed 40 percent of its storage capacity using Hitachi Dynamic Provisioning. The organisation has a Hitachi SAN located in an AT&T collocation centre a few miles from UHC headquarters in Oak Brook, Illinois. It now takes just half of one employee's work hours to manage the SAN, Naglich said.

One feature of Hitachi Dynamic Provisioning that has been useful to UHC is being able to expand the size of a storage volume on the fly, Naglich said. In the past, if demand for capacity grew, it was necessary to create a new, larger volume and migrate the data to it, he said.

Hitachi also launched its Storage Reclamation Service, a set of paid services in which Hitachi will assess the storage needs of customers and potential users and help them with planning, migration, storage reclamation and other tasks.

Customers will only have to pay if Hitachi exceeds the customer's pre-set expectations for storage reclamation, the company said. Prices will vary by customer, but for a typical enterprise with 50 servers and 50TB of storage, the service should cost less than $100,000 (£60,000).

Zero Page Reclaim is available immediately for the Universal Storage Platform V and VM, and automatic dynamic rebalancing is coming on 30 June. The new features are free for customers with software maintenance contracts. Hitachi Dynamic Provisioning for these platforms is free for the first 10TB and starts around $10,000 beyond that.

Hitachi Dynamic Provisioning is also coming to the company's midrange Adaptable Modular Storage (AMS) 2000 family of equipment, beginning 3 August. The Zero Page Reclaim feature will be added for AMS at a later date. Pricing has not been set for the software on AMS.