Time To Get Familiar With iSCSI, Serial ATA

My advice? Get trained on iSCSI yesterday, and start learning about Serial ATA today.

Earlier this month, the Internet Engineering Task Force (IETF) officially made iSCSI a "proposed standard," which means the final standard is coming shortly. iSCSI is a way to send SCSI data over TCP/IP networks. Though it allows low-cost storage networks to be built using IP instead of Fibre Channel (or what some call "poor man's SANs"), it is most commonly used to connect existing SANs over IP.

Vendors haven't been waiting for the specification. They jumped the gun with iSCSI products a year ago, and the product class is already maturing--since famous and not-so-famous vendors have already come to market. Solution providers who have already built networks using iSCSI say interoperability between iSCSI products from multiple vendors is by no means assured. But interoperability seems to be much less an issue than when Fibre Channel started taking hold.

So what if iSCSI networking isn't as inexpensive as promised, or if a lack of 10-Gbit Ethernet limits performance? These questions will be answered as more products come to market.

We're still in the early-adopter stage, which means you'll probably have to spend time educating customers about iSCSI and what it can do for them. But by getting the products in for evaluation and getting the necessary training and certifications as soon as possible, you'll find the technology a great way to differentiate yourself from other storage solution providers.

Unlike iSCSI, where vendors had plenty of products in place long before the standard was finalized, Serial ATA (SATA) products have been long in coming.

SATA is a natural evolution of the ATA specifications, which are used in the bulk of the hard-drive business. SATA-based hard drives are software-compatible with ATA drives, meaning that they work with the same operating systems, applications and drivers without the need for modification.

Yet SATA drives use a thinner cable and smaller connectors, which makes it easier to cool a PC or even build a smaller one. Compared with their ATA counterparts, SATA drives also feature improved data throughput speed and error correction. Unlike ATA drives, SATA drives also are hot-swappable. And since the drives have point-to-point connections, forget master-slave settings.

Although the final SATA specs were adopted some time ago, Seagate has been the only supplier of SATA hard drives until now, and the product has been available in limited quantities. Western Digital just started producing them, and other vendors should be doing so shortly. So SATA drives are in short supply, and there should be a $10 to $15 price premium with SATA for some time.

Is SATA for you? If you build desktop PCs, you'll want to start testing SATA hard drives and host bus adapters as quickly as possible so you can be ready to implement them as supply increases. Once that happens, there will be little reason not to use SATA in your systems.

Still, don't expect customers to ask for SATA. You'll have to be proactive in selling the technology. If you build servers, SATA hard drives are not such a pressing issue, since most customers will probably still prefer SCSI hard drives for speed and reliability. But if you build low-cost storage arrays, you'll love SATA. Besides providing easier installation (thanks to smaller cables and connectors), SATA will allow you to offer inexpensive storage arrays with hot-swappable hard drives.

Still reading and writing,

Joseph F. Kovar

JOE KOVAR is the storage editor for CRN