IBM System Storage DS3200 Express

IBM's latest System Storage DS3200 aims to offer SMBs a low-cost DAS appliance to consolidate storage across multiple servers. Performance, expandability and ease of use are high on IBM's agenda, and it looks to hit all three targets, delivering support for the latest 15K SAS hard disks, a top capacity of over 14TB and a management interface full of wizards.

This 2U rack chassis is based on LSI Logic's Engenio 1333 Storage System and can handle up to two controllers, each equipped with a pair of x4 SAS ports, with one used for host connections and the other for hanging IBM's EXP3000 12-bay SAS expansion units from. Up to three expansion units are supported, but if you want dual redundant drive channel pairs you'll need the optional dual-port expansion cards. The Express models include either single or dual controllers along with the necessary cables and PCI-E HBAs.

LSI is also behind the scenes for the management act, as the bundled Storage Manager 2 Client utility (SMC2) is its Engenio Simplicity Manager software. The main interface makes light work of installation, as you just connect up the controller's Ethernet management ports and leave it to run. It can automatically create logical drives, and there's a good selection of array types to choose from, although RAID6 isn't supported. Hosts are then assigned to logical drives and you can place multiple hosts in groups that share the same mappings. Called partitioning, the base system supports four partitions, but you can license up to 16. Alternatively, you can allow one host only to use a logical drive. However, we encountered a glitch, as SMC2 appears to be incapable of identifying SAS or FC hosts, so you need to assign them to drives manually.

With a single controller in the review unit, we linked it to a Supermicro dual 3GHz Xeon 5160 server running Windows Server 2003 R2 and equipped with an IBM-branded LSI Logic SAS controller. We mapped a quad-drive RAID5 array to the host port, and Iometer reported a raw sequential read rate of 562MB/sec - a result of the server HBA aggregating its four 3Gb/sec SAS lanes. As expected, write operations were slower, but an average of 136MB/sec is certainly nothing to sniff at.

Along with active/active controllers, IBM also supports Microsoft's MPIO (Multipath I/O) for creating redundant paths from hosts to storage volumes. If one controller fails, the drive will be reassigned to the other controller, and a valuable feature is that IBM doesn't charge for its DSM (device specific module). IBM's dynamic capacity expansion allows more drives and expansion units to be added on-the-fly, and selected logical drives expanded into the new space. There are more options, as FlashCopy takes point-in-time snapshots of selected logical drives, while VolumeCopy creates a duplicate of one logical drive to another location within the same appliance.

DAS is often the best solution for SMBs looking to improve their server storage prospects, as it's simple to install and deploy. The DS3200 more than lives up to these expectations - at an affordable price.

Author: Dave Mitchell