Rackable iSCSI system stacks up

Meeting growing storage requirements is no longer just a matter of accommodating a few more files. Thanks to legislation that mandates the archiving of e-mail and customer records and to the increased use of multimedia and VoIP apps, storage needs can double or triple in a very short time. 

Although FC (Fibre Channel)-based SAN technologies offer easy-to-scale, high-performance solutions, there's also a place in enterprises for less-expensive, high-capacity systems. To that end, iSCSI SANs offer an easy, flexible, low-cost way to add storage for servers in situations where maximum throughput is not required.

Rackable Systems is best known for its blade server systems and Linux-based clusters, but its iSCSI appliances also show a good grasp of what the market wants. The S3118-iSCSI appliance system I received for review was a no-frills 3U storage system that holds as many as 18 250GB or 400GB SATA RAID Edition drives. The S3118 doesn't include storage management software, but the configuration software is excellent, performance is good, and the price is hard to beat.

Nuts and bolts

The Western Digital RAID Edition drives are engineered to run continuously -- rather than intermittently, as workstation drives are designed -- and are rated at a million hours MTBF (mean time between failures). The RAID Edition drives counter the objection some administrators have about SATA drives, namely that they are not as reliable as SCSI or FC drives. Only time will tell, but the RAID Edition drives should be reliable enough for most server applications.

In addition to slots for 16 drives in front, the S3118 has two additional drive slots in back, as well as an Ethernet management port, two Gigabit Ethernet network ports, and the standard assortment of server ports. The S3118 can function as a dumb iSCSI target or be configured as a Windows or Linux server using the two rear drives as mirrored boot drives. This requires installing the OS and then configuring the storage system to work with it, but it gives you a full server for the same cost as the basic appliance. A NAS version of the same hardware is also available.

The system I received had 18 250GB RAID Edition hard drives, an AMD Opteron 248 processor, 4GB RAM, two 3ware RAID controllers, two Gigabit Ethernet ports, and the management processor with a separate out-of-band Ethernet management port. Along with the dual controllers, redundancy features include dual power supplies and dual Ethernet interfaces. Naturally, multiple boxes can be clustered as well.

As an iSCSI appliance, the system is very easy to set up. It is configured with a default IP address on its embedded management interface, so a serial terminal or KVM connection is not necessary to make the initial configuration, just a Web browser. After the initial network configuration has been completed, the rest of the configuration is handled through the Wasabi Storage Builder 1500i for iSCSI Appliances software that Rackable uses for iSCSI services. The system comes with a default configuration, but changing the RAID configuration or volumes is simple and straightforward. In addition to software iSCSI clients, the S3118 supports Intel and Alacritech iSCSI accelerators.