SAS Promise Becomes Reality
After years of sightings and speculation, Serial Attached SCSI (SAS) products are finally hitting the market.
Adaptec, LSI Logic and Promise Technologies are among the vendors who have recently announced SAS products and solutions.
Adaptec has announced two SAS RAID controllers, a new host bus adapter (HBA), a pair of SAS subsystems, a four-bay internal storage enclosure, and a SAS starter kit (with Seagate as the SAS drive vendor). LSI Logic announced a new MegaRAID SAS storage adapter, and Promise Technologies has unveiled a storage system that plays on SAS's biggest selling point the ability to combine high-performance SAS drives with lower-cost SATA drives in the same backplane for a tiered storage approach within a single box.
SAS backplane arrays are going to be an incredible thing, allowing people to tier all of their storage within one box," said Mike Karp, senior analyst at Enterprise Management Associates.
And that could make information lifecycle management (ILM) technology available to a wider audience.
Thomas Bayens, director of corporate marketing at Promise Technologies, thinks that in the small and mid-size business (SMB) space, most redundant subsystem controller backplanes will switch to SAS backplanes to accommodate SAS and SATA drives. Bayens also expects that many enterprise systems except those designed for Fibre Channel drives will also support SAS backplanes.
The Time is Right
With all the major pieces finally in place, the time may finally be ripe for SAS adoption.
"We look at this as an enterprise-quality infrastructure, and if it's deployed too early, then customers will have a bad experience and it delays the ultimate rollout of the technology," Adaptec Director of Product Marketing Paul Vogt told Enterprise Storage Forum. "We wanted to make sure that all the pieces had matured, including the host bus adapters, the RAID software, the enclosure management and cables."
"As with any new technology adoption, getting all the bugs worked out across all the vendors of these products takes time," said Charlie Kraus, director of LSI's HBA division. "From recent press releases, you can see that we are through this phase now."
Bayens said that with SAS HBAs and drives starting to ship, the technology is ready for prime time. "If there are no SAS HBAs or SAS drives, there is nothing to connect the JBOD to," Bayens said.
The development process on the subsystems side took longer than expected, according to Maxtor Interface Architecture Manager Marty Czekalski.
"Subsystems generally have a longer development process," Czekalski said. "However, we are starting to see many SAS products being introduced onto the market, and will continue to see SAS solutions being introduced in 2006."
SAS HBAs: Who Leads?
The early SAS HBA market appears to be led by Adaptec and LSI. Promise does not currently have its own SAS HBA, although one is likely to debut next year.
LSI Logic claims that it now holds more than 80 percent of the SAS market and was first to market with HBAs.
"LSI gained its significant lead on the market by being first to market with solid four-port and eight-port SAS controllers and expanders," said Kraus. He added that LSI Logic also expects to be the first with PCI-Express and SAS 2.0 solutions.
"For SAS controllers, the only competitor we have today is Adaptec," Kraus said.
Vogt disputes LSI's claim that they were first with SAS HBAs, noting that IBM was the first to start shipping SAS back in January with a server called the X366 that uses Adaptec technology.
Karp noted that historically, Adaptec and LSI have been the leaders when it comes to SCSI. The very first SCSI controller came from NCR Microelectronics, which became Symbios Logic and then LSI Logic via acquisition. Adaptec was always the prime competitor.
"The competition is really going to be for the controllers and the actual controller silicon," said Karp. "Right now, the leaders are clearly Adaptec and LSI, but don't be at all surprised to see Promise, which has very good marketing savvy, come out and become a very credible contender."
Where is the SAS Market Headed?
IDC sees SAS adoption occurring first in servers and internal storage, and then in external storage, said IDC Director of Storage Research Dave Reinsel. "IDC believes SAS is initially an internal play as a likely successor to all the SCSI-based systems," he told Enterprise Storage Forum.
Others, such as Promise, Maxtor, LSI Logic and Adaptec, share that opinion.
"Ultra320 is the end of the line for parallel SCSI," Kraus said. "Within two years, we see the SAS market overcoming the SCSI market, driven by the major OEMs who are switching to SAS from SCSI now."
Kraus also sees potential for SAS as a small SAN interconnect technology. SAS expanders are really switches, he said, allowing multiple servers with SAS ports and SAS JBODs or RAID arrays to be interconnected. These expanders can allow many fabric services, such as zoning by port or address. Kraus expects that very low cost infrastructures will be built using this technology, with the potential to be disruptive in the small to medium business (SMB) space.
Reinsel said IDC believes that adoption of SAS as a SAN technology in the SMB market will be hindered because of Fibre Channel complexity. "Ethernet is fine and systems based on SCSI have sufficed," he said. "SAS and SATA, along with iSCSI, will enable these SMBs to deploy more cost-effective SANs while leveraging a more traditional infrastructure."
Adaptec's Vogt is also among those who don't think that SAS will replace Fibre Channel.
"SAS has really been focused on a disk connect and improving that piece of it, so we don't see SAS replacing Fibre Channel or iSCSI as a network protocol," Vogt said. "We see the OEMs leading the way in deploying these in controlled configurations. The channel will be slower to mass adoption as they get comfortable with the technology and deploy it in multiple configurations."
Karp points out that although Fibre Channel dominates the high end, the majority of storage that's out there is on SCSI. A lot of it is direct attached and a lot of it is in midrange arrays.
"SCSI is moving into high end arrays as well as mid-size arrays, and there is a very good chance you'll see it eroding the segment that Fiber Channel has," Karp said, "although the need for data is growing so rapidly that SAS can grow without having to do that."
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