Dell Intros External Storage With 2.5-Inch SAS

Dell is the latest storage supplier to ship external storage enclosures equipped with 2.5-inch SAS drives. And it claims the availability of the compact drives has renewed interest in direct attached storage (DAS) for some applications.

"Introducing a DAS product in this day and time seems unfashionable, but we're finding a DAS resurgence," says Praveen Asthana, director of Dell Enterprise Storage. "SAS is making DAS more scaleable, and we're seeing more applications around DAS. Exchange 2007 can get performance in a DAS without needing a SAN."

Like HP, IBM, Sun, and other suppliers, Dell started replacing older SCSI drives with 2.5-inch SAS drives in its servers over two years ago. While others have been offering JBOD with 2.5-inch drives and Infortrend has shipped external RAID subsystems with them, Dell has hung back, but now claims to be in the "knee of a trend" upward, making it economically feasible to offer 2.5-inch external storage as well.

Dell claims its PowerVault MD1120 takes up 70 percent less space and 50 percent less power than 3.5-inch drives. Each 2U enclosure houses up to 24 drives. Up to 144 drives can fit into 12U of rack space. Up to 21 Tbytes can be handled by one RAID controller (using 144 146-Gbyte drives per enclosure, with up to three enclosures per RAID port).

Dell won't say whose drives it's using, but Fujitsu, Hitachi, and Seagate all offer 2.5-inch SAS drives in capacities of 36 Gbytes, 73 Gbytes, and 146 Gbytes. In addition, Seagate recently unveiled a 300-Gbyte 2.5-inch drive it says will increase a large-scale migration to that form factor for enterprise drives by 2010.Seagate is shipping its 300-Gbyte, 2.5-inch drives to OEMs for qualification, but so far no products have surfaced. A Seagate spokesman says he expects OEM qualifications to start during the second half of this year.

Meanwhile, even smaller, denser drives are planned: Fujitsu has been working on 2.5-inch "terabyte" drives for months.

Dell doesn't anticipate the smaller form factor drives taking the place of enterprise 3.5-inch array drives anytime soon. But for organizations interested in a quick fix for storage-hungry servers, as well as in the ability to manage both servers and DAS with the same software, the vendor pushes this lower-end solution.

Dell's advocacy of 2.5-inch SAS is part of a larger migration toward the form factor for smaller-scale storage kit. At least one analyst thinks it's the wave of the future. "Any vendor who does not have a statement of direction public or private for introduction of a 2.5-inch, SFF [small form factor] high performance storage solution for entry and midrange in the next year or two will either be left behind, or scrambling to come up with excuses as to why they don't have a solution," says Greg Schulz of the StorageIO Group.

Have a comment on this story? Please click "Discuss" below. If you'd like to contact Byte and Switch's editors directly, send us a message.