Hitachi helps storage shops reclaim capacity

In the ongoing quest to make more efficient use of storage capacity, 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.

Enterprises traditionally have had to allocate set amounts of storage in virtual volumes for particular applications or users, then take down those volumes and create new ones if less or more capacity was needed. This has led to a big problem with trapped capacity, according to Enterprise Strategy Group analyst Mark Peters.

"People don't use a huge percentage of what they've bought," Peters said. Thin provisioning, which lets administrators allocate capacity for the short term rather than guessing at long-term needs, has helped solve the problem, he said. But change comes slowly in the storage arena, so many organizations still haven't taken advantage of tools for boosting capacity, he added.

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 (storage area network). 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 that is being introduced Wednesday. The 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 virtualize and manage all the storage capacity in a multivendor 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 centers across the U.S., has about 40 terabytes of storage capacity for all its applications. One of the organization's jobs is to gather data from many medical centers and process it before sending it on to the U.S. government.

UHC says it has reclaimed 40 percent of its storage capacity using Hitachi Dynamic Provisioning. The organization has a Hitachi SAN located in an AT&T collocation center 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.

The IDG News Service is a Network World affiliate.