Lowering storage TCO

The cost of physical space is probably the least-evident factor affecting the TCO (total cost of ownership) of storage solutions. Nevertheless, every IT manager knows that when buying a new storage array, the footprint of the new equipment will add another significant cost to its acquisition price.

Depending on your company’s location, your lease can cost hundreds of dollars per square foot, and storage arrays — with their bulky, 3U-sized stacks of drive enclosures — are probably the worst space hog in your infrastructure. Add the area needed for switches, tape libraries, cooling units, and UPSes (uninterrupted power supplies), and the overhead cost for each TB of online storage becomes significant.

We usually dismiss this as one of those unfortunate-but-inevitable facts of life, but some interesting developments in drive technologies presented by Adaptec, HP, Maxtor, and Seagate at the recent HP World Expo open new hopes for the future.

In a nutshell, taking advantage of new technologies such as SAS (serial attached SCSI) and SATA (serial ATA), disk arrays will become faster, smaller, and more flexible for business requirements.

A quick techno-recap. Both SAS and SATA depart from the old parallel approach and use serial connections between drives and controllers, which allow faster transfer rates, more devices per controller, and smaller form factor for connectors. Despite those similarities, SAS is the technology that you should consider for enterprise-class performance on transactional applications, while SATA offers less expensive storage for PCs, entry-level servers, and reference data.

If you’re wondering how these two technologies affect storage density, here’s the answer. The same SAS controller can connect both SCSI and SATA devices, which means being able to mix those drives in the same enclosure with obvious space and cost saving. Moreover, the small connectors favor the deployment of 2.5-inch SAS drives, which can significantly lower the space requirements, for example, for blade servers or disk enclosures.

Probably the most exciting part is that SAS is not years away. Actually we should see the first products ship in 2004. In fact, HP World attendees had a first taste of SAS in action, with an HP ProLiant DL380 server, mounting an Adaptec FPGA host adapter, and Seagate’s 147GB 10K RPM (rotations per minute) drives.

At the same show, Maxtor demoed its new 3.5-inch SAS drives, with models spinning at 10K and 15K RPMs, happily co-existing with the company SATA drives in the same enclosure, aptly retrofitted by Adaptec. As we all know, the same layout is not viable using parallel technologies, which require different controllers, hence separate boxes.

Perhaps even more interesting is Seagate’s demo of the new 2.5-inch SAS drive, a miniature jewel that according to the company is about 140 percent faster and fits in a fraction of the space of existing 15K RPM models.

I, for one, can’t wait to get my hands on the upcoming SAS products. They promise great technology and a discount on their overall cost, built in by design.