The network storage supplier’s thin provisioning software will certainly give it an edge over other major suppliers’ storage virtualization systems, including those from IBM Corp and Hitachi Ltd. But analysts confirmed that it is not a world first. Other vendors already selling thin provisioning systems include start-ups 3ParData Inc, LeftHand Networks Inc, and Permabit Inc.

3Par CEO David Scott said: We were the first to ship thin provisioning in July 2003. If NetApp has trouble with the simple arithmetic concept of first, then customers should be careful about trusting them to handle the complexities of fine-grained virtualization mapping tables.

Alongside thin provisioning, NetApp also launched hardware updates and a writable snapshot facility. But the thin provisioning is the highest profile of the announcements. Called FlexVol, it is a free-of-charge addition to the latest version 7G of the OnTap operating system that powers NetApp’s hardware.

This is going to be extremely useful, said Enterprise Storage Group analyst Tony Asaro. Thin provisioning cuts down storage administration workload, and hugely reduces the amount of unused disk space that must be provided for applications to grow into.

Customers don’t want to have to go out and buy enough storage capacity to grow into over the next 18 months. With thin provisioning they can buy a third of what they’re going to need later, Asaro said.

IBM’s SAN Volume Controller and Hitachi’s Lighting Tagmastore Universal Storage Platform do not offer thin provisioning. NetApp’s implementation is going to give them a competitive advantage. Customers have certainly said that it’s one of the most attractive features of 3Pardata’s system, said Asaro.

NetApp’s new software runs in its filers and arrays, which might appear to represent a vote in the current debate over where storage virtualization is best located in the array, on a smart switch, or on an appliance or server. But Asaro said: This isn’t about that. That is a totally different issue.

NetApp’s other announcements include the launch of software that creates writable snapshots called FlexClone, which 3ParData again claimed that it has matched since 2002. FlexClone will allow 256 rewritable snapshots per volume. NetApp said the demand for the feature will be driven by the need to create data clones for testing and development work that because of the way they are created as snapshots do not consume the same amount of disk space as a full copy of data. It pointed to anecdotal evidence including SAP’s estimate that 70% of its licenses are used in development systems.

This will be priced a little higher than our SnapRestore software that 90% of our customers already use. We expect the same sort of take-up. Basically it’s not priced to gouge, NetApp said.

The other NetApp announcements were the addition of Hewlett-Packard’s XP12000 disk array to the support list for NetApp’s Gfiler gateways, and the addition of Fibre Channel ports on the front of the Gfiler to allow it to be attached directly to host servers. The latter will expand the applications for NetApp’s software tools, the company said.

Thin provisioning is needed because the process of allocating disk space to applications is laborious. As a result, IT staff commonly over-allocate capacity to create plenty of headroom for applications to grow into, so avoiding the need to repeat the allocation job too soon. That results in disk utilization rates that average only 40% or 50% in typical businesses.

Thin provisioning allows administrators to allocate space that is not actually physically present. Unlike conventionally allocated space, thin provisioned space is not committed for use until it actually written into by an application.

This means that large amounts of space can be thin provisioned to give growth headroom, and as applications grow and need that space, administrators simply need to add more disks. Unlike the process of allocating space to applications, the process of adding disk is extremely easy according to Asaro.

Because it is part of a virtualized system that pools disk space across multiple arrays, thin provisioning also allows growth headroom to be shared between applications, sparing the need to predict exactly how fast each application will grow. The bet on how much excess space is needed can be hedged across multiple applications.