NAS kit uses Linux to good effect

Adaptec's Snap Server 520 combines ease-of-use and performance with good expansion options

The market for network-attached storage (NAS) appliances is a volatile place, but Adaptec’s Snap Server family has lasted longer than most and the company has strengthened an already strong line-up with the latest Series 500 appliances. The range comprises three devices aimed at companies looking for a rack-mount storage solution with good expansion capabilities.

The 520 reviewed here is a good quality Supermicro 1U appliance equipped with a 2.2GHz AMD Opteron 248 processor partnered by 2GB of PC3200 memory. Four 250GB Sata drives are provided in hot-swap carriers, though for the price we would have expected 500GB disks.

A key feature of the Snap Servers is that they all run Adaptec’s Linux-based GuardianOS, while virtually all the competition in this market uses Windows Storage Server 2003. In terms of features there’s not actually much to separate either OS, but the software-managed Raid arrays of the 520 are likely to cause a small hit on overall performance.

The 520 offers excellent expansion potential via an optional serial attached SCSI (SAS) controller card that allows up to four external SANbloc S50 SAS expansion units to be daisy-chained off the back. These can increase capacity to 26TB and when fitted appear to the OS as JBODs, which are then configured as individual Raid arrays. Storage managers can also increase online capacity by expanding existing volumes into the extra space.

The web interface is well designed and easy to use, and client support is as good as the Windows-based alternatives. The 520 can serve up storage to Windows, Unix, Linux and Mac clients if required.

Along with a local user and group database, both NT and Active Directory domain authentication are supported and quotas at the directory and user level help control usage.

ISCSI support is provided, and we found performance particularly good; the open-source Iometer reported a very healthy data transfer rate of 105MB/s over a Gigabit Ethernet connection to a single target.

The bundled CA eTrust software provides local antivirus measures, although only scheduled on-demand scanning is supported.
Standard backup features include snapshots for point-in-time copies of selected volumes. This is augmented by the pre-installed BakBone NetVault Workgroup Edition that includes five client licences and a free upgrade to a 500GB virtual tape library. Set-up is a bit fiddly as the 520 must be managed by another system with the NetVault server component loaded. Nevertheless, with this in place the 520 can be managed as a NetVault client where shares are selected and secured to the virtual tape library (VTL) or to a physical tape drive.

With prices starting at around £218, Adaptec’s optional Snap enterprise data replicator (EDR) adds an extra dimension that allows files and folders to be distributed from a source to multiple appliances or from one appliance or multiple sources to a single destination. It uses a separate interface fired up from the main web console and all systems running the EDR client, including Windows and Linux machines, can be selected as sources or targets.

It’s good to see Adaptec putting some serious resources into the Snap Server family and the end result is a good quality range of small and mid-sized storage appliances. The 520 is a fine example as it delivers an excellent range of features plus some serious expansion potential and tops these off with good performance.