Atrato, Inc., a new storage vendor, emerged from stealth mode this week to unveil the company’s first product: the Velocity1000 (V1000) storage system. The new product offers 11,000 Input/Output operations per second (IOPS) and 50 terabytes of raw disk capacity in a 3U rack. The company relaunched itself back in February, when it changed it name from Sherwood Information Partners to Atrato and announced $18 million in funding. It also revealed some of its big name backers, including Jesse Aweida, founder, former president and CEO of StorageTek; Tom Porter, formerly CTO of Seagate; Gary Gentry, SVP Maxtor, Seagate; and Dick Blaschke, an IBM and EMC veteran.
The V1000 product is a unique storage appliance aimed at the high performance computing, digital entertainment and web sectors, where I/O performance and cost are big driving factors. The offering is designed to address a growing problem in high-end storage: the imbalance between storage capacity and I/O performance. Capacity is doubling every 18-24 months. But access speeds — data transfer rate, seek time and rotational latency — are only increasing around five percent per year. With capacity increasing exponentially and access speeds increasing linearly, application responsiveness is suffering. This is especially true for applications that have a random data access pattern.
Atrato’s goal was to create a high performance, highly dense, but energy-efficient storage system. It uses its patented Self-maintaining Array of Identical Disks (SAID) technology to construct a highly dense, sealed enclosure that is guaranteed to be maintenance-free for at least three years (more about how this is done in a just a moment). The company also claims it can achieve all this with much lower energy use than conventional storage. “At a given performance level, we use 80 percent less power than commercially available systems today, whether it’s NetApp, LSI or DataDirect Networks,” says Dan McCormick, Atrato co-founder and CEO. The company says a V1000 setup can deliver 17.3 IOPS/Watt versus a typical industry figure of 4 IOPS/Watt.
The majority of the power savings come from the building blocks of the disk enclosure. Instead of using 3.5 inch enterprise-class SATA or SAS disks, Atrato engineers decided to use lots of mobile-class 2.5 inch SATA disks in their drive enclosure. Mobile SATA disks are built for power constrained platforms like laptop computers, but tend to be lower capacity — 100 GB to 320 GB. The smaller size of the disks compared to their enterprise counterparts actually contributes to their energy efficiency, since the moving parts don’t have to travel as fast or as far.
The overall approach is to use mass parallelization of these relatively small disk drives to construct a more efficient system. This is analogous to the manycore approach for processors, where lots of simpler, less powerful cores are used to build a high performance computer. In the case of the V1000, the more granular storage model improves random access performance and energy efficiency at the same time. Efficiency is also increased by the system software, which manages data placement on the disks in order to optimize the seek operations.
The Atrato engineers had to overcome a number of drawbacks of mobile-class drives to make the system reliable. In general, these devices exhibit rotational vibration instabilities. When they get too close to each other, drive performance can drop by 70 percent or more. Heat and signal integrity can also become a problem when they’re packed closely together. The engineers were able to design proprietary drive packaging that circumvents these problems. According to McCormick, with this special packaging, they’ve been able to derive enterprise-class performance from mobile-class hardware.
The company guarantees three years of maintenance-free operation for their enclosure, with no disk replacements required. By contrast, in a conventional enterprise setup, when a drive fails, a light blinks on the front panel and then a call is made for somebody to come out and perform the drive replacement (hopefully the worker pulls the right one and doesn’t bring the system down in the process). In most cases, when the offending drive is sent back to the factory, no problem is detected. “We take that same process and move it inside the box,” says McCormick.
Within the SAID enclosure is a virtual spare — extra capacity that is ready in case of a drive failure. In fact, at any given time, the system is replicating data from 15 to 20 of the most suspect drives. So when a failure occurs, the drive is taken off-line and put in the “drive hospital.” Diagnostics are used to determine what’s wrong. In many cases, the error can be isolated and the drive can be put back online. During that time, the user is unaware anything has happened, since there has been no interruption of service or performance hit.
By anticipating drive failure, McCormick says they’ve been able to eliminate any single point of failure. Even if the hardware is beyond redemption, the drive just remains off-line for the life of the product and the software works around it. The system employs a variety of RAID technologies (RAID 5, 6, 10 and 50) as well as its predictive rebuild technology to support this level of reliability. According to testing done by Atrato engineers, they’ve been able to empirically model a three to five year time frame for sustaining the product’s performance and reliability.
As in any redundant storage system, a certain amount of capacity has to be sacrificed. The system allows users to configure trade off capacity with some level of reliability. At the high end, McCormick says as much as 80 to 90 percent of the raw storage capacity is available to the user. More conservative users can drive the usable capacity down to 50 percent or even lower if they choose to maintain the highest levels of reliability. For many customers, this would be a reasonable tradeoff, since storage capacity is cheap and getting cheaper, while drive maintenance costs are exactly the opposite.
Atrato’s initial customers are likely to be users that have strict performance and power requirements and/or require maintenance-free operation. The first customer announced this week is SRC Computers. They have integrated the V1000 into a system for a government sector customer who needed high levels of random access performance. That SRC system achieves 20,000 IOPS with 14 terabytes of usable capacity.
Atrato is not announcing its pricing at this point, but McCormick says that a 20 terabyte (raw capacity) system starts somewhere in the $150K range. There are certainly less expensive storage systems out there on a price/gigabyte basis (based on high-capacity 3.5 inch SATA), but on a dollar/IOPS basis, the highly parallelized Atrato architecture gives the V1000 the edge.
In fact, the company isn’t going head to head against mainstream enterprise storage solutions. Systems with really big storage tend to be used by applications that don’t need extreme levels of I/O performance or are accessing data sequentially on the disk. Atrato’s niche is where near-instantaneous data transactions are required. McCormick sees his competition as the emerging technologies of flash disk and RAM-based external storage. At this point, he thinks those technologies are not quite ready for prime time because of a combination of price, performance and reliability issues. But, he says, when solid state drives make sense, they’ll be happy to bring them into their product line.