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January 19, 2010

Startup Takes Aim at Performance-Killing Vibration in Datacenter

by Michael Feldman

At SC09 last November in Portland, Oregon, I met a fellow named Larry Gordon who related this story:

“I’m riding a train to San Francisco, and I’m reading a newspaper. The train’s vibrating and my arms are vibrating and the newspaper’s vibrating. I can still read the newspaper, but it takes more concentration, so I don’t read as fast as I normally do. It’s just more work to focus on a moving target.”

Makes sense. But why is he telling me this story at a conference about supercomputing? As it turns out, Larry Gordon is the vice president of marketing for a startup called Green Platform Corporation, and the scenario he’s describing on the train is analogous to the problem that hard disk drives encounter when reading and writing data in a datacenter environment — a problem, he believes, the company has solved.

According to Gus Malek-Madani, Green Platform’s founder and CEO, vibration in the datacenter forces a disk drive to work extra hard to perform reads and writes, degrading performance. And not just a little. Independent tests indicate as much as two-thirds of I/O throughput is being lost due to vibration. Worse yet, as performance suffers, the disk has to do additional work to access data, slowing down the entire compute system and raising power consumption proportionally. Tests indicate that as vibration increases, energy use can more than double for a given job.

The source of all this vibration includes the hard drives themselves (the mechanical motion of the spinning platter and actuator arm movement), cooling fans, and chiller pumps, as well as the cumulative vibration reverberating back and forth between racks. While most solid state components are relatively immune to vibration, spinning disks are not. “The performance of these drives is incredibly damaged by vibration,” Malek-Madani told me.

Malek-Madani has made a 25-year career of using carbon fiber to battle the forces of vibration. In fact, Green Platform is an offshoot of another company of his called Composite Products, which offers anti-vibration racks and shelves for the high-end audio/video and scientific markets. Malek-Madani got the idea in his head that computer disks might also benefit from vibrational dampening, and when some initial tests (on a desktop PC) proved out, he decided to pursue the solution that would make commercial sense: disk storage in datacenters.

The solution he and his new company came up with is rather simple: build whole racks out of carbon fiber material and other composites to dampen datacenter vibration. (Carbon fiber is the same material used in aircraft and golf clubs for its superior strength, weight advantages and vibration damping characteristics.) The Green Platform rack, called the AVP-1000 (prototype pictured below) is designed to replace the traditional steel rack with a carbon fiber one. The AVP, which stands for Anti-Vibration Platform, is built as a standard 19-inch enclosure and is compatible with typical storage server form factors.
AVP-1000 Prototype

Up until now, hard drive manufacturers were concerned with vibration, but almost exclusively from a reliability point of view. It’s well understood that too much internal vibration inside the drive mechanism risks a disk failure. When vibration is detected, the actuator arm can freeze or slow down in order to prevent a head crash. The idea here is to protect the data media at the expense of a temporary performance drop. But the design treats the symptom, not the cause, and does nothing to address the cumulative effects of vibration in the environment. Green Platform treats the effects of normal and ongoing levels of ambient vibration in datacenters as well as shocks from seismic causes, rolling dollies, elevators, subways, construction, etc.

All of this is part of the more general problem of hard disk technology, which is stuck between the digital and mechanical worlds. As the density of disk media has become greater, more bits per square inch can be stored on the media, making it increasingly difficult for the actuator arm and read/write head to find a specific piece of information. Thus, while storage capacities have increased, access times have not kept up.

Likewise, the effect of mechanical vibration also works against the trend of denser media. Returning to Gordon’s original analogy of reading a newspaper on a train, it’s as if the read/write head at the end of the actuator must adjust to ever-smaller fonts. The idea that datacenter vibration is causing significant I/O performance degradation is supported by the poor performance hard disks often exhibit in the field compared to the manufacturers’ specs.

Recent tests seem to back up these claims. Lab testing by Sun Microsystems’ Systems Dynamic Characterization and Control team in San Diego looked at the effect of sequential I/O on SATA drives. They found that as the vibration level increased, disk throughput dropped from 40 to 15 MB/second. At the same time, the amount of energy the system consumed to write 10 terabytes of data increased from about 1.7 to 4.5 kilowatt-hours. The Sun testing also found that Green Platform’s AVP rack effectively dissipates nearly all of the vibration through the critical range of frequencies, restoring performance close to the no-vibration state.

Another set of tests performed by Q-Associates, a system integrator, compared I/O performance of the Green Platform AVP racks and steel racks in a Tier 1 datacenter environment. These tests used the more robustly built SAS drives (2.5-inch), which, by design, should be more resistant to vibrational stress. What they found was the AVP racks increased IOPS performance significantly: 56 to 246 percent for random reads and 34 to 88 percent for random writes, with the larger file sizes benefitting the most.

According to Malek-Madani, the overall result is that the Green Platform racks boost storage throughput by as much as 250 percent, while proportionally decreasing energy consumption related to powering and cooling the storage equipment. There is also evidence that suggests vibration dampening will lengthen MTBF (mean time between failure) for storage hardware, thus reducing support costs.

The price premium for a Green Platform rack compared to a traditional metal rack is significant. According to Gordon, an AVP will cost four to five times that of a steel rack (which runs around $2,000). But to Gordon, that’s not the way to look at this solution. Since the AVP-1000 improves performance and lowers energy costs, the rack can pay for itself in less than 12 months — sometimes much less. Where data throughput, as opposed to data capacity, is the limiting factor of the storage infrastructure, an AVP solution means you will need fewer storage servers. If you can cut your storage infrastructure by a third, payback happens on the first day, says Gordon.

In fact, according to him, the AVP delivers the type of performance enhancement that solid state drive (SSD) caching provides. “Datacenters are spending tens of thousands of dollars on high-speed caching to improve storage performance,” notes Gordon. “Essentially, we provide similar benefits, and we’re much lower cost than storage caching.”

Although Gordon and Malek-Madani think their AVP solution has broad applicability to the enterprise storage space, their initial entry point into the market will be in high performance computing, where storage performance is often the bottleneck. This is especially true in applications like seismic data analysis, which can take days, weeks or even months to process. Shortening the cycle time for that analysis is a critical path to revenue for these oil and gas companies. Beyond HPC, they see a $5 billion dollar market opportunity in the enterprise.

Today, the company is offering the AVP rack in limited quantities for pilot studies in partnership with certain storage OEMs and system integrators. (For the time being, the company is keeping the names of these interested parties to itself.) The initial business model will involve partnerships with some of these same integrators and OEMs, who will bundle their product with storage servers. According to Gordon, they have already begun a number of these relationships and are making “new connections” on a daily basis, and some of these relationships are in the process of being formalized.

They’re also looking for an influx of funding, which to date has been accomplished internally, presumably through Malek-Madani’s Composite Products business. External funding is being sought to continue testing, add a vice president of sales and help scale up manufacturing.

In the short-term, the company is looking to develop some case studies from the pilot studies and expand the program to additional user sites. “We realize that we’re making some pretty extraordinary claims,” admits Gordon. “At least early in the market, we expect people will want to prove this to themselves.”

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