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|How 4Gb/sec FC can help|
From a user perspective, the rollout of 4Gb/sec FC may turn into a non-event. Few have saturated their 1Gb/sec FC links, let alone their 2Gb/sec links. "We're running 1Gb/sec now and haven't been hampered at all," says Jay Chalfant, supervisor of PC and network support at Questa College, San Luis Obispo, CA. He's hoping to jump to 2Gb/sec at a significant discount when new 4Gb/sec products come out in volume next year. "I expect the price for 2Gb/sec products will drop at that point," he says. Of course, 2Gb/sec products will eventually disappear as vendors shift production to 4Gb/sec products.
"We push really big files through and we're not even taxing our 1Gb/sec link," says Todd Thomas, CIO, Austin Radiological Association, Austin, TX, which does medical imaging. He recently upgraded his 25TB SAN with 53 hosts, an EMC Symmetrix DMX1000 and two EMC Centera arrays attached. That required talking to a lot of vendors and "nobody even mentioned 4Gb/sec," he adds.
Likely early adopters
Maybe a company "that's trunking multiple 2Gb/sec lines today to get more bandwidth will really want 4Gb/sec," says FCIA's Jones, but he couldn't immediately recall any such companies. The vendors think that if they build it, price it comparable to 2Gb/sec products, and ensure backward compatibility and interoperability, the customers will come. "There is really no decision for IT managers to make. They will get 4Gb/sec when they buy new products," Jones concludes.
Early adopters are more likely to be video production firms than corporate IT. "We use an FC switch with our NAS, and have a mix of 1Gb/sec and 2Gb/sec links. We don't have a bottleneck with FC, but we always get the newest, fastest technology," says Maciek Maciak, chief engineer at Charlex, a New York digital video production house. Charlex uses dual 2Gb/sec FC links to connect its Silicon Graphics workstations directly to storage. "With 4Gb/sec FC, we might need just one," Maciak suggests.
Even at large enterprises, few IT managers see a need for 4Gb/sec other than for digital media. "Unless someone wants it for video editing, 4Gb/sec isn't something we absolutely need," says Richard Kruszewski, network administrator at TBWA/Chiat/Day, an advertising agency based in Los Angeles. To date, no one has expressed dissatisfaction with performance. "For us, 2Gb/sec is more than adequate," he adds.
That's not to say that users won't want the extra performance in the future, especially if it costs roughly the same. History suggests that users eventually take advantage of performance increases and are soon looking for even more. "Customers are always asking us for continued improvements in FC products. Improvements in speed ultimately result in improved productivity, and 4Gb/sec is simply another speed improvement," says Doug Pickford, director of server market and product strategy at Hitachi Global Storage Technologies.
One possible use for 4Gb/sec, suggests ESG's Asaro, will be storage consolidation. For example, a company may need to virtualize and consolidate dozens or even hundreds of hosts at the FC port level. "This has the potential to overtax today's bandwidth. With 4Gb/sec FC, you wouldn't saturate the pipe," he explains.
It may also save organizations from buying more switches and ports. "Today, we get 3:1 servers to ports. With 4Gb/sec, we could get 6:1 or even 10:1," says Asaro. That could reduce the need to buy more ports.
The road ahead
The transition to 4Gb/sec FC is just the latest milestone on the FC roadmap. Next up is 8Gb/sec FC, expected in the 2007 to 2008 timeframe. From there, the picture gets a little cloudy. There is 10Gb/sec FC already, which uses a different fiber and is used mainly for interswitch linking. It doesn't provide backward compatibility, so it would require an entire forklift upgrade.
Others have suggested 12Gb/sec as the next step beyond 8Gb/sec, but that seems unlikely. Given the electronics science involved, "if you are not doubling, the technical challenge gets strange. Doubling is always better from an electronics standpoint," says FCIA's Jones. If nothing unforeseen pops up in the meantime, 16Gb/sec would roll out around 2010 to 2011.
Some users may simply skip 4Gb/sec. "We are fine with 2Gb/sec. We are nowhere near saturating it. We may ignore 4Gb/sec and go to 8Gb/sec when it comes out," says Joe Comeau, information systems manager at the University of British Columbia, Vancouver.
Whether you plan to go to 4Gb/sec FC or not, you're likely to get it anyway when vendors switch over to 4Gb/sec technology and discontinue their older products. With no price penalty, and with backward compatibility and interoperability assured, you might not even notice you've made the change.
This was first published in November 2004