Tandberg Data DPS2040 review

Data deduplication is rapidly gaining in popularity but we've yet to see a really affordable option for small businesses. Tandberg Data could have the answer. Its DPS2000 series offers this as standard but costs little more than a standard NAS appliance.

In this exclusive review we look at the four-bay DPS2040 that comes with the AccuGuard Server Edition software licence for one system. This provides source-side deduplication for Windows servers and combines it with drag and drop restoration and backup facilities for SQL Server and Exchange.

The AccuGuard software works with any storage location, and you create shares or persistent iSCSI targets on the appliance via its own web interface. AccuGuard checks all data on the client as it's backed up, only sends unique blocks to the appliance, and also applies LZ compression.

Tandberg claims deduplication ratios of 20:1 but has no published figures to back this up. The ratio will depend entirely on the type of data, its compressibility, the rate of change and the retention period. The advantage of client side data reduction is that network overheads are reduced as only unique data is sent over it.

The drawback is each server has its own datastore on the appliance so deduplication can't be applied across multiple backups at the target. From the AccuGuard interface you create protection plans that include the source data, the destination and a daily, weekly or monthly schedule.

To test deduplication ratios we ran our own set of tests designed specifically to look at performance for file server operations. Using a 4GB data set consisting of 1,000 files, we introduced controlled changes within a percentage of the files. Once the first full backup had completed, 2% of the data was modified in 40% of the files prior to each subsequent backup. After a two-week simulation we saw AccuGuard deliver a ratio of 6.25:1. This compares well with the A-Listed CA ARCserve r12.5 which returned a ratio of 5.3:1 in exactly the same test.

Restore operations are simple as you just choose a job within a plan and explore its contents. Files and folders are restored using drag and drop, and because the contents of every job are listed you can go back to any point in time.

The datastore indexes are stored locally in the host's registry so you must back these up separately. It's a pain that the software can't manage this essential task but the manual does show you which keys must be copied.

Tandberg's DPS2040 has to be one of the lowest cost deduplication solutions currently available. It delivers good storage savings, is easy to use and the appliance itself offers a wealth of other storage-related features.

Author: Dave Mitchell