After I covered the launch of Atrato’s self-maintaining array of identical disks (SAID) product, there were some unanswered questions, which I blogged about last week. Shortly after that, I had a followup call with Atrato’s chief scientist Sam Siewart and executive vice president of marketing Steve Visconti to tie up at least some of the loose ends.
There were inconsistent reports on the size of disk drives used by the Atrato system; the officials confirmed they are using 2.5-inch SATA drives.
More detail was desired on exactly what disk errors the system can fix and how. That’s proprietary, Siewart said, which I’d anticipated, but he gave one example – the system can do region-level remapping on a drive with nonrecoverable sector areas. The system also runs continual diagnostic routines in the background and can fix such problems proactively, meaning it can find such an error and force the controller to remap the sector before a user’s I/O comes in.
I asked them if their IOPS number (ranging anywhere from 10,000 to 20,000 IOPS depending on which news source or press release you were reading) was achieved through testing or estimated based on a 512KB block size. To which they replied, “definitely tested.” The average result of those tests was about 11,000, though their mysterious government customer reported 20,000 with a tuned application. “What we need to do is have discipline in talking about approximately 11,000 and then describing how the results may vary,” Visconti said of the inconsistent numbers that appeared in the first round of Atrato coverage. The bandwidth is about 1.2 GBps.
Part of the problem when it comes to talking about this system is that so many of the parameters are variable, including price. “Pricing ranges from the low hundreds [of thousands of dollars] to upwards of 200K depending on the configuration,” Visconti said. So in a way, all of us who reported anything in that range were right. Performance is the chief configuration factor that influences price–a system that’s populated with 160 slower, higher-capacity drives will be more at the $100,000 end of the range. “Most customers are opting for higher-speed 7200 RPM SATA drives,” Siewart said. Added Visconti, “We shouldn’t be quoting a precise number.”
Clarification on the 5U/3U question – 3U is the size of the storage array, but doesn’t include the size of its controller, which might be either 2U or 3U depending on whether or not it’s an x3650 from IBM (2U) or a souped-up one from SGI (3U). Atrato’s developing its own controller to be announced later this year.
The array attaches to servers using a modular front-end that today is shipping with a 4 Gbps FC interface that can also accomodate NFS. “We’re close on 8-gig Fibre Channel,” Siewart said, and working on iSCSI, 10 GbE and InfiniBand as well. Distance replication and mirroring also remain on the roadmap.
Meanwhile, it seems Atrato is looking for marketing help.