Storage-server hybrids coming into vogue

When designing a data centre, conventional wisdom holds that servers should do the thinking while storage systems should hang onto the data. But some industry heavyweights have begun seeing things a little differently.

IBM's machines based on its Power5+ processor now have features that enable a storage-server hybrid design. And this month, Sun Microsystems began selling a hybrid of its own, "Thumper," a 7-inch-tall, 24-terabyte system officially called the Sun Fire X4500. And HP is tackling the idea with new blade servers.

While neither company expects hybrid systems to dominate, they argue there are some situations where it's good to have mixed abilities. IBM likes the idea of processing to intelligently manage storage tasks such as indexing, while Sun sees the combination as good for those who need a powerful, reliable way to pump data such as video streams onto a network.

"The lines are blurring," said Illuminata analyst Gordon Haff.

Historically, storage was often built into a server or directly attached. But within a big-computing infrastructure, storage increasingly has been relocated into a separate domain to increase efficiency and to ease management and maintenance.

For that reason, some see storage-server hybrids as a throwback.

"To be honest, we're seeing the market move in the opposite direction (than in the past)," said Patrick Rogers, vice president of products and partners at networked storage powerhouse Network Appliance. "People are disaggregating storage. They want to pool it for utilisation and efficiency reasons.

Indeed, revenue from networked storage systems is growing faster than from storage overall, according to an IDC study. Where the market for networked storage devices increased 15.4 percent to US$2.8 billion from the first quarter of 2005 to the first quarter of 2006, overall storage sales grew more slowly at 6.7 percent to US$5.8 billion.

But Sun is bullish about the idea, and its respected x86 server engineer, Andy Bechtolsheim, built a start-up called Kealia around the approach. Sun acquired Kealia as part of an effort advance x86 server designs quickly to carve a place in the market it had shunned for years.

The case for Thumper
"I expect we'll be selling this in probably 60 percent of customer installations. I think it'll be a high-volume unit," said Graham Lovell, Sun's senior director of systems.

The X4500 had been code-named StreamStor at Kealia, which planned to sell it as a streaming video device. Sun built a much broader "Galaxy" x86 server line around Kealia's designs, but initially cancelled the StreamStor project. When John Fowler took over the x86 server group, though, he resurrected it and gave it the new code name, Thumper.

"StreamStor ... denoted a complete package including streaming software. Nobody was coming up with a better code name, and it was very confusing," Fowler said. "So one day on the way to work, I decided to call it 'Thumper' after the fairy tale rabbit, with the specific idea that this would be such a stupid name that someone would come up with something better. No one did, and from now on I'm not allowed to name anything."

Video streaming still is one of the uses that Lovell envisions for the X4500. Specifically, an X4500 can be a staging area to store video data while they're being streamed reliably to customers. The video archive could be stored on lower-performance devices, he said.

Another use is high-performance computing. The Tokyo Institute of Technology uses multiple systems to pump data in and out of a cluster of Sun servers that in June was ranked the world's seventh fastest supercomputer.

And he said large retail customers are contacting Sun about using the X4500 to store recent surveillance video. Processing power could let customers immediately retrieve specific video from recent weeks, process and compress data, or automatically handle archiving duties.

Some don't share Sun's enthusiasm. "Sun is out at the front of the pack on this, but whether or not there's going to be any market demand for that is a real unknown. It's a risky offering," said Pund-IT analyst Charles King.

But one company is betting hybrid systems will be useful: Greenplum, a 30-person start-up that sells business intelligence software for tasks such as identifying purchasing trends or customer Web surfing habits. The company announced a deal with Sun on Wednesday to sell its software bundled with Sun's hardware.

"For business intelligence applications, it is the killer platform. It's far and away the most powerful general-purpose platform out there for this kind of work," Greenplum chief executive Scott Yara said in an interview. The system uses Greenplum's modified version of the PostgreSQL open-source database, called BizgresMPP, and Sun's ZFS file system, Yara said.

The system will be sold in multi-Thumper configurations so large data sets can be scoured for information, he added. "Our software clusters together to build a very large warehouse."

The Greenplum-Sun combination also illustrates one drawback: Storage-server hybrids' unconventional design means that many companies won't know how to put them to use. As a result, many analysts expect hybrids to be popular chiefly as special-purpose appliances, in which a company combines the hardware and software so its customers don't have to figure out how.

Big Blue's hybrid ideas
IBM's foray into hybrid systems is beginning with an appliance approach. Big Blue's TotalStorage DR550 system combines a server, System p, running IBM's AIX version of Unix with a DS4000 storage system, said Clod Barrera, a distinguished engineer and chief technical strategist for IBM's System Storage group. The processors handle tasks such as indexing or deciding which data should be shuttled from fast disks to slower tape.

Eventually, such systems will be very busy handling, managing and retrieving data. "Over time it will become very, very processing intensive," Barrera said.

The company's high-end storage system, the DS8000, is a variation of its System p servers. The Power5+ processors and other features in those systems let administrators carve these "Shark" systems into separate partitions.

Today, that means a DS8000 can appear to be multiple different systems for different business units. Later, it will mean server workloads can run on the storage system.

"We have not shipped that kind of function, but we believe that is something that will be done on Sharks," possibly in coming months, Barerra said. Processing could be offloaded from more expensive mainframes, or some applications such as searching, could be boosted. "It might be cheaper to outboard that search somewhere close to the disks, so I can save myself all the ups and downs across the various software layers," he said.

There are an increasing number of storage tasks that benefit from processing, he said. Among them are encryption and enforcement of access rights to make sure only authorised people can retrieve data.

HP blades: A third way Hewlett-Packard, which sells more x86 servers than any competitor and has a solid storage business to boot, sees a blades as the way to build hybrid products.

Because some customers need more hard drives in servers, HP moved its servers from prevailing 3.5-inch disk drives to smaller 2.5-inch drives so that more could be tucked into the same server case. But for true hybrids, the company steers customers toward its new C-Class BladeSystem chassis.

That blade server can accommodate either conventional processing blades or storage-only blades with plenty of hard drive spindles, said Dwight Barron, chief technologist for HP blades. HP therefore can offer a flexible ratio of storage to processors to meet a variety of situations -- including tasks such as archiving Microsoft Exchange data that requires more processing abilities than stand-alone storage systems can supply, he said.

"We're able to mix and match the ratio of CPU blades to storage blades," Barron said. "We can take that number well above the tight range the industry has seen in the past.... We believe that trend has some legs."