EMC Ups the Storage Ante

CEO and president Joseph Tucci made no bones about the importance of EMC's recently launched Symmetrix DMX800, 1000 and 2000 disk arrays. "We have bet the farm on the DMX line," he told a large crowd gathered at the New York Grand Hyatt Hotel earlier this month. "This year, we expect to take significant market share."

EMC engineers haven't just given Symmetrix a cosmetic upgrade. They have redesigned the subsystem's guts to create a "direct matrix" architecture, which includes what they call the first high-end modular structure. These new subsystems do not use the traditional bus system,which many liken to a single highway within a system through which all data flows,or the switch design that rival Hitachi Data Systems uses. Executives say this is the first design on the market that "is non-blocking and non-sharing."

In other words, internally the device gives each front-end controller its own direct path through the cache to the back-end controller. Theoretically, the subsystem's future versions can grow to provide up to 128 GB of cache, with up to 32 independent cache regions, and up to 32 concurrent 500-Mbps paths through cache, with up to 16 GBps of aggregate cache throughput. The architecture can handle up to 32 independent cache regions, each with a separate logic access. This enables IT managers to adjust the processing and access power necessary for each application.

Dave Donatelli, EMC's executive vice president of storage platform operations, says it was the company's largest project ever, with 300 million hours of run-time in beta testing. It also has more than a dozen patents pending. "We looked at a switch architecture," he says. "In fact, we patented one, but we also felt it could not go far enough." Brian Gallagher, an engineer who worked on the project, says the innovation challenge was less in the physical layer and more in the logical layer. "We really looked at the problem differently," he explains. "Then we figured out how to physically [solve] it, using standard, off-the-shelf physical components. But we had to invent the logical layer."

The DMX line has three device levels, including the modular Symmetrix DMX800, which can be configured with 16 to 120 drives for a raw capacity of up to 17.5 TB. It has 16 2-Gb Fibre Channel ports, 16 2-Gb Fibre Channel I/O ports and 32 GB of cache. On the higher end, the monolithic Symmetrix DMX1000 and the Symmetrix DMX2000 subsystems are integrated, single-bay configurations. The 2000 features 96 to 288 drives for a maximum capacity of 42 TB, while the 1000 features 48 to 144 drives for a maximum of 21 TB. All of the devices are based on the Enginuity storage operating system.

The DMX design has new eight-port 2-Gb Fibre Channel and ESCON directors for up to 96 channel connections to more than 8,000 network-connected hosts. All the previous Symmetrix products internally used a SCSI interface.

And in another departure, EMC now supports parity RAID (3 1 and 7 1) for data-striping with parity. Previously, EMC only supported RAID 0 or 1 for data mirroring. Customers say that EMC finally took on parity RAID because they were getting hurt in the market on the higher costs of their disk drives. Moreover, EMC executives say the direct-matrix design actually enhances the power of parity RAID.

Interestingly, Tucci notes there was another product that was supposed to be delivered after the current Symmetrix but before the DMX line. But company executives believed the market opportunity for DMX was now. "A year ago, we took a big bet and canceled that project," Tucci says.