Interoperability Lab Plugs SAS

Trying to avoid the mistakes of their SCSI predecessors, Serial Attached SCSI (SAS) vendors have completed their third interoperability test -- a.k.a. plugfest -- at the University of New Hampshire InterOperability Laboratory (UNH-IOL).

After more than 100 engineers gathered earlier this month to kick the tires of 21 vendors SAS gear, David Woolf, head of the UNH-IOL SAS testing group, pronounced the technology ready for primetime. For most participants, the test was the last plugfest before SAS products ship, and the last before the first shipment of any SAS drives.

The plugfests were held to ensure that SAS products manufactured by different companies will interoperate with other vendors’ SAS and Serial ATA (SATA) wares. SATA interoperability is an issue because SAS and SATA drives will share space in the same storage systems next year (see Vendors Strut Their SAS, Mixed Drives in the Mix, and Report: SATA & SAS to Share Systems).

An executive of one SAS vendor says testing is also especially important for this technology because original SCSI drives had serious interoperability issues that weren’t discovered until after they shipped.

“When SCSI came out, there were an ungodly amount of compatibility issues,” the executive says. “Hookups to HBAs and RAID adapters wouldn’t work, and SCSI vendors got hit pretty hard.”So it’s no surprise that so many engineers showed up to check things out. David Woolf says a plugfest with around 20 vendors usually draws no more than 50 engineers. This one brought out more than twice as many. “It shows SAS is one of the top priorities because they sent a lot of people,” he says.

Companies at the November plugfest included:

Two other vendors that participated asked that the lab not identify them.

While some of the engineers tested systems, most tested components such as HBAs, chips, boards, hard drives, expanders, and cables they will sell to OEMs. Woolf says the testing was rigorous.

“It was a trial by fire for the technology and the implementation,” he says. Gear was hammered with simulated traffic and made to work with a range of different setups. “We put the devices in the worst-case scenario. If there’s a problem, it’s a good thing to find it early. We didn’t see a major showstopper.”There were at least a few minor glitches where devices didn’t adhere to SAS standards, and Woolf says he expects to see some devices back at the UNH-IOL SAS test bed before they ship. There’s another SAS plugfest tentatively scheduled for late April 2005, but many vendors expect to have shipping products in the first quarter. Seagate already has SAS drives sampling with OEMs, and Finisar and LeCroy have SAS testing products available (see Seagate Struts SAS, Finisar Intros SAS Analyzer, and LeCroy Announces Compliance Test Suite).

— Dave Raffo, Senior Editor, Byte and Switch