NetApp has reduced its datacentre storage requirements from 25 to six racks and cut its power requirements by $60,000/year through thin provisioning and previously unannounced de-duplication technology.

In 2006 its datacentre storage had poor disk utilisation - less than 40 percent - at the same time as it was facing growing space, cooling and power constraints. NetApp had 50 systems' worth of disk storage racks, and most of it was spinning empty space. It still needed power and cooling though.

It consolidated this storage onto ten of its newest storage systems. To do this it used de-duplication and thin provisioning (Flexvols) in its Data ONTAP O/S

In a data consolidation white paper NetApp says it put secondary data onto NearStore arrays. These include: " A-SIS de-duplication, a technology that eliminates duplicate data.' It is a block-level de-duping capability which is described in a deployment guide as being 'extremely efficient'.

When a volume (Flexvol) is created on NearStore, A-SIS can be run to de-dupe the data: "A-SIS only stores unique data blocks in the flexible volume and creates a small amount of additional metadata in the process. Each block of data has a digital “signature,” which is compared to all other signatures in the flexible volume. If an exact byte-for-byte block match exists on the flexible volume, the duplicate block is discarded and its disk space is reclaimed."

There is no de-duping across Flexvols which limits the amount of space that can be reclaimed. NetApp claims a doubling of storage efficiency through A-SIS. This, on the face of it, compares poorly with claims of 20:1 de-dupe ratios for Data Domain, 25:1 for Sepaton and up to 50:1 by EMC's Avamar technology. However, these do refer to cumulative de-duping of repeated backup runs.

NetApp also used thin provisioning FlexVol technology. This spoofs applications into thinking they have all the storage allocated they need when they actually get only as much as is needed to write data.

Chris Bennett, NetApp's VP for Core Systems, said: "We believe that if more focus is put on getting increased work out of fewer disks while enabling widespread use of higher-capacity and lower-power disks, NetApp can help customers dramatically reduce power consumption."