IBM has upgraded its SAN Volume Controller, with added support for SSDs and promises a boost in performance with or without flash storage.

SAN Volume Controller (SVC) 5.0, due to ship on 6 November, is the latest version of a storage virtualisation appliance that can control storage capacity from IBM and other system vendors. It will take advantage of technology IBM researchers developed in Project Quicksilver, which the company said last year had achieved one million read operations per second using SSDs (solid-state drives).

Though SVC 5.0 falls slightly short of those lab results, clocking in at 800,000 read operations, for the first time it allows enterprises to put SSDs inside the SVC. It also includes upgrades that will boost the performance of HDDs (hard disk drives) in the virtualised storage environment, according to IBM.

SSDs are fast emerging as a favoured place to store data that applications such as transactional databases need to access quickly. Because they have no moving parts, they can outperform groups of linked HDDs while making better use of available capacity, space and energy. But capturing the full benefits of SSDs requires more than simply sliding an SSD into a slot, industry analysts advise.

IBM's SVC can be linked over a SAN (storage-area network) to storage systems from other vendors, including Hewlett-Packard, EMC, Sun Microsystems and NetApp. It virtualises the combined capacity as a single pool of storage, giving enterprises greater flexibility in provisioning and using storage resources. It can control a maximum of 8 petabytes of storage.

The mark of one million read operations with Project Quicksilver was achieved using a nonstandard configuration of the SVC, said Chris Saul, IBM's marketing manager for storage virtualisation. The shipping product will be able to deliver 800,000 read operations with four pairs of SVC systems linked together, he said. SVCs, which are servers one rack unit high (1U), are sold in pairs for redundancy.

The SSDs each will have 146GB of capacity, and there are slots for four of them in a single SVC, with mirrored SSDs in its pair. A base configuration of a single pair, without the SSDs, will cost US$40,000.

Other improvements in the coming upgrade are designed to improve the performance of any storage used with the controller. For the first time, the SVC comes with four 8Gb-per-second Fibre Channel interfaces, up from the four 4Gbps ports in the previous version. In addition, the new hardware has three times the maximum cache, at 24GB per pair, and a faster processor. Though results will vary depending on how much storage is attached to the controller, the SVC 5.0 platform will be able to deliver as much as double the I/O operations and megabytes per second of the previous SVC, Saul said.

By adding SSDs, IBM has taken a high-performance product and given it more speed, said analyst Mike Kahn of The Clipper Group. In the past, some enterprises have worried about virtualising some of their high-demand storage because of possible limitations in the horsepower of an appliance such as IBM's SVC, he said.

A virtualisation appliance, like a middleman, needs to find each bit of data within all the storage it controls. Companies have to build storage virtualisation systems with enough speed to withstand their busiest possible day for applications such as transactional databases.

With its high-performance SSDs, IBM has boosted the scalability and speed of an SVC to a point where more enterprises can confidently use it with a large part of their storage, Kahn said.

"You'll get by with fewer appliances in your solution," Kahn said. By the same token, a virtualisation environment with many SVCs can be even larger, he added. In the largest organisations, that may mean using storage virtualisation on a large scale for the first time.