Although you often find statements that seem critical of disk drives in this column, I never criticize disk drives per se, but rather how we use them. As of late, I've been interested in the innovative use of disk drives in storage arrays. The latest news from Xiotech fits right into this discussion, providing further proof that the storage industry is fast turning evolution into revolution in rethinking its approach to disk drives.
As you may have read, Xiotech began shipping two new storage solutions last week, the Emprise 5000 and the Emprise 7000. The arrays differ in capacity and scalability, but what's interesting is that neither mounts the usual crowd of disk drives we're used to seeing in every storage solution. Instead, they replace the drives with ISE (Intelligent Storage Elements) datapacs, sealed containers that offer 10 to 20 times the capacity of a single disk drive plus a bunch of built-in reliability features that will make your head spin.
The technology was brought on board in a little-publicized acquisition from Seagate, which included the transfer of about 100 employees to Xiotech.
What's in those containers? Depending on requirements, an ISE datapac can host 3.5-inch disk drives, 2.5-inch drives, or even SSDs (solid-state drives) while maintaining the same form factor. Judging from a presentation I saw, two datapacs can comfortably fit in a 3U enclosure, leaving room for controllers, power supply, battery modules, and the like.
As for the "intelligence" part, using smart controllers and advanced data protection techniques, ISE can stretch the MTBF (mean time between failure) to hundreds or thousands of times that of a single disk drive. Moreover, when a drive fails, the ISE controller will attempt a factory rebuild of the drive (think very low-level formatting), which should bring the device back to life more than 50 percent of the time, according to Xiotech. And when the drive is repaired, data rebuilding occurs automatically and without disruption.
Compare this with the hours or days it can take to rebuild the content of a large SATA drive, for example, and you understand why Xiotech has invested in delivering this technology to its customers.
But how does the performance of these new ISE arrays compare with traditional approaches to disk drives in competing arrays? Because some storage vendors (EMC, for example) snub independently reviewed benchmarks such as those published at the SPC (Storage Performance Council) site, comparisons are difficult. But there are many other vendors that publish their own benchmark results, including Fujitsu, HP, IBM, and Sun. Xiotech has also filed SPC-1 (random I/O) and SPC-2 (throughput) benchmark results for review, and it seems that the Emprise line has fared well, better than its competitors, not necessarily in sheer performance, but in price/performance ratios.
I still hope that the Council will soon make comparing those results a little easier.