Dell thinks small with 2.5-inch SAS storage sidecar

Wee SAS for your DAS

Far less glamorous then bleeding edge solid state drives, small form-factor SAS disks are, all the same, making tracks in corporate storage systems.

That is — the disk vendors are making most of the promises at this point. Not a lot of big names in the storage game are offering 2.5-inch SAS (Serial Attached SCSI) arrays right now , but hey, they're alive and well in the two-dimensional space of company roadmaps and Powerpoint slides from the likes of EMC, IBM, and NetApp.

But adoption may well pick up now that Dell is taking the plunge. The vendor has launched the PowerVault MD1120 storage expansion enclosure made specifically for the wee disks. Apparently, this is part of a renewed vigor around direct attached storage (DAS) for applications such as Microsoft's Exchange.

The 1U box works as a JBOD (just a bunch of disks) that connects to Dell's PowerEdge server. It holds 24 2.5-inch SAS drives for a maximum capacity of 3.5TB. Compatible disks are 15,000RPM SAS drives in 36GB and 73GB sizes, and 10,000RPM SAS drives in 73GB and 146GB sizes.

Up to 21TB can be handled by one RAID controller, with three enclosures plugged into a RAID port and using a dual-ported controller. (We'll save you the math, that's 10.5TB on a single-port controller.)

The major selling point for using 2.5-inch disks in an array is the itty-bittyness. Dell claims its storage box takes up 70 per cent less space and consume 50 per cent less power than one with 3.5-inch drives.

Meanwhile, we've heard disk vendors talking up the improved reliability and fault detection with SAS over SATA for mission critical applications. Combine constant space concerns with the increasing storage capacities of 2.5-inch drives being sold, and you've got some vendors and customers eyeing 3.5-inchers.

A bit of recent history — 2.5-inch drives for enterprise gear showed up first in servers and the little guys certainly caught on. With 300GB capacity small form-factor enterprise SAS disks on the horizon, things are looking like they'll be mixing with 3.5-inchers in storage relatively soon.

There's been some head poking already. Early this year, Infotrend began shipping storage arrays using small form-factor SAS disks. Perhaps Dell's enthusiasm will bring more vendors out of the woodwork to announce more definitive plans for 2.5-inch SAS in their entry and midrange kit. ®