Product Reviews

Microsoft's Windows Storage Server 2003 (WSS2003) may have given NAS appliances a new lease of life, but the iSAN 1600SA moves them into the heady realms of the SAN. The storage appliance on review is WSS2003-powered but Evesham has added FalconStor's iSCSI Storage Server software which, at its most basic level, allows it to present itself as an iSCSI target device.

The software has been written specifically for WSS2003 and integrates only with the remote management interface. There's nothing to see from the local console, as the software merely adds a new iSCSI tab to the main remote interface. The process of setting up iSCSI targets is a lot more fiddly than, say, for the Overland Storage REO RA2000, but once you understand the required steps it's simple enough. The first job is to create storage pools used for setting up logical units, which are iSCSI virtual disks. Any remaining physical storage can be used in standard NAS operations for providing simple shared network storage. Storage pools can consist of an area on a single disk or a virtual file spanning multiple disks. Next, you carve up the pool into logical units. Each one can be expanded on-the-fly into any unused space in the pool, which is a powerful feature. CHAP authentication from network hosts can also be requested, while access permissions for each logical unit can be set.

There's more to do, as portals must be created and assigned to specific IP addresses on the appliance, and iSCSI initiators need to be identified and assigned to logical units. For the latter, you need to log on your initiators to the appliance, which will identify and add them to a list ready for selection. FalconStor supports a wide range of hardware and software initiators, and for testing we plumped for Microsoft's version. Once the appliance had been set up, we added the target portals from our test host systems and logged on to the selected iSCSI target. We could then access and configure the new disk space from the Disk Administrator as though it were a locally attached drive.

For performance testing we started with a Supermicro dual 1.7GHz Xeon server running Windows Server 2003 and logged on to a single iSCSI target

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drive. Using the open-source Iometer utility, we assigned one disk worker to the drive. Using 64KB transfer requests, ten outstanding I/Os and 100 per cent sequential read operations we saw an impressive average transfer rate of 84MB/sec - more than twice as fast as the RA2000. We piled the pressure on by adding two more servers with all three logged on to the same iSCSI target and also through the same network port. Running separate instances of Iometer on each system returned a cumulative total of 80MB/sec.

Performance is impressive but it's worth noting the review system was supplied with only the basic Storage Server software. FalconStor also offers a huge range of options including server clustering and mirroring over iSCSI, volume snapshots and backup options designed to integrate with third-party backup software.

The 1600SA also impresses in the hardware stakes as, although the Chenbro chassis leaves something to be desired with build quality, Evesham has filled its cavernous interior with plenty of quality components. A high-calibre Intel server motherboard sits in the driving seat along with a pair of 2.66GHz Xeon processors, and Evesham has generously included 4GB of memory. The operating system is handled by a pair of Maxtor SATA drives connected to a simple LSI Logic RAID card and configured as a mirrored array, while the four 250GB Western Digital SATA drives are linked to a separate Adaptec 16-port RAID controller and set up as a RAID5 array.

There's room for a total of 16 hot-swap drives in the chassis and it's worth noting that the Western Digital drives are the latest RE (RAID Edition) models. Whereas the Raptor models focus on performance, these new Caviar drives are aimed specifically at RAID applications where reliability is more important. The drive heads have been improved and the new Betta power controller produces less heat. Hot-plug capabilities have been enhanced with a new internal three-stage mating sequence, and Western Digital's TLER (time limited error recovery) aims to reduce the risk of drive errors causing RAID arrays to become degraded. The only drawback of the Adaptec card is the backplane connectors are individually connected to the controller, resulting in a mess of cables. 3ware's new MultiLane Infiniband-based cards could offer a tidier solution and we plan to look at these next month.

There's no denying the iSAN 1600SA brings together a slick storage solution with huge expansion potential and plenty of fault tolerance. ISCSI performance is comparatively good and we were particularly impressed with the FalconStor software. This mates perfectly with Microsoft's WSS2003 and provides good management facilities, easy configuration and plenty of options that will get the most out of your iSCSI SAN.