The best thing that ever happened to mass data storage? No, it's not flash memory, and it's not the hard disk or tape drive, either. No, it's actually software -- in other words, logic that can overcome the frailties and limits of physical and semiconductor storage devices.
Think RAID and its ability to squeeze more reliability and performance out of relatively inexpensive hard drives. Think SSD controllers, which work around the inevitable failures that flash memory chips suffer. And think Intelligent Storage Element (ISE), an intriguing product sold by X-IO, a venture-backed company that was spun off from Seagate 10 years ago and maintains a close relationship with the HDD giant.
According to X-IO, the ISE is a clever packaging of hard drives and intelligence that can achieve impressive levels of reliability and performance. Each ISE consists of a sealed, "self-healing" pod of enterprise-class hard drives (and, in some models, flash memory) that the company says perform well enough to compete head to head with pure-flash SSD.
It seems X-IO has thoroughly rethought enterprise-class HDD storage. For instance, the way it mounts its enterprise-class hard drives in its 3U-size ISE module makes them considerably more resistant than usual to vibration and heat (both known disk killers). Dual ports on each drive make for extra availability, too, and the ISE is smart enough to fix itself on the fly, at more of a finger-grain scale than RAID usually does.
In typical RAID systems, when a particular hard drive fails, that unit gets completely disabled, and the entire array gets rebuilt in a process that often takes several minutes. In contrast, the ISE is programmed to cope with individual read/write heads or platters that go bad and work around them by remapping data nearly instantly. If at all possible, the rest of the troubled drive's heads and platters remain in service. X-IO CTO Stephen Sicola told me this enables the ISE to recover from hardware failures in about one second.
The ISE, which is shipped as a sealed "black box," is designed to stay operational for at least seven years (it's warrantied for five), which significantly reduces its total cost of ownership, Sicola said. (X-IO actually monitors field-installed ISEs 24/7 and alerts customers when there's any sign of trouble.) Other storage companies could use this approach, but they don't, he said, because it would cut into high-margin service revenues.
"I don't care if small pieces fail. The group of drives is what matters," he said. Compared to how most drives are treated in datacenters, those in an ISE "are in an easy chair, watching the football game with the A/C on."
This self-contained approach enables high performance, too, Sicola said. This starts with storing data automatically and intelligently across an array of as many as 20 drives. The fastest ISE, with a pre-RAID capacity of around 29TB, can deliver as many as 13,000 I/Os per second. What's more, unlike many other array products, the ISE does not slow down as it fills with data. "We get 100 percent performance at 100 percent capacity."
X-IO recently added flash memory to its product, driving performance even higher -- to as much as 60,000 IOPS in an OLTP environment. The unit's internal logic constantly analyzes data uses, and it uses an ROI calculation every three to five seconds to figure out if any particularly hot records should be moved to SSD. The hybrid HDD/SSD-based ISE also contains some nonvolatile DRAM, helping it to deliver "full SSD performance at only one-10th to one-20th of the cost."
Target applications include virtual desktop infrastructure, video streaming, handling VMs, database management, and business intelligence. For now, the box attaches via Fibre Channel, but additional interfaces are planned. X-IO customers range from Microsoft to the A&P grocery chain to the Church of Jesus Christ of Latter-Day Saints, which is using more than 4PB of ISE-based storage to hold certain genealogy records.
I don't know it the ISE does all that X-IO claims it can do. For whatever it's worth, Sicola is an old storage hand, having started out at Digital Equipment, as did several key members of his technical team. I notice that Enterprise Storage Group has called the ISE a "game changing technology." The product certainly strikes me as worth a look by any enterprise or cloud services provider seeking to keep up with ever-accelerating demand for extra reliable, extra-performance storage.