One of the major new forces in storage that is coming into its own at the Storage Networking World Fall 2003 conference in Orlando is low cost disk drive technology based on the serial ATA (SATA) standard.
But while the technology is the main attraction in several new "enterprise class" storage systems, most vendors admit that it's role in the data center will be as an option for secondary storage.
Silicon Graphics Inc (SGI), Mountain View, Calif., and LSI Logic Storage Systems Inc., Milpitas, Calif., both claim to be the first to introduce SATA technology in enterprise class storage systems. SGI introduced two new disk storage systems Tuesday, the SGI InfiniteStorage TP9300S and TP9500S.
According to SGI, the new SATA models will play a key role in SGI's Integrated Lifecycle Management solution, working with SGI servers and shared filesystems to automate data movement in a multi-tiered storage architecture.
The TP9300S can support up to 112 drives and over 16TB of raw capacity. Each TP9500S array has a maximum capacity of 56TB. Users can can combine multiple TP9500S arrays into a single filesystem up to Terabytes or even petabytes, according to SGI.
LSI's bid for the SATA market came in the form of new storage systems using the Maxtor MaXLine SATA hard drives and LSI's 5884 and 2882 controllers. The new systems are designed for midrange and enterprise application environments needing lower cost storage and are willing to sacrifice some performance without losing the availability, data integrity and features currently achieved with Fibre Channel based storage systems.
Also entering the SATA market, nStor Corp., Carlsbad, Calif., introduced and demonstrated its Wahoo-SATA 2Gbit Fibre Channel to SATA RAID controller, which has the ability to connect up to sixteen SATA disk drives, providing up to 4TB of capacity. The new Wahoo-SATA RAID design is nStor's second generation 2Gbit RAID controller which uses the same RAID features found in nStor's Fibre-Fibre Wahoo controller now available with Serial ATA disk support. The Wahoo-SATA RAID controller family has three different host interfaces (2Gbit Fibre Channel, Ultra320 SCSI, and 1Gbit iSCSI) to satisfy SAN, direct-attached and networked storage requirements. The nStor SATA RAID controllers have the ability to connect up to sixteen Serial ATA disk drives, providing up to 4TB of capacity.
The big draw of SATA technology is the price tag. When you consider that hard drives represent thirty-to-eighty percent of the cost of storage systems and that SATA drives are roughly one-third the cost of Fibre Channel disks the economics become compelling. While many end users are anxious to realize the cost benefits of Serial ATA, it's important to realize that SATA in "enterprise class" storage systems doesn't mean users should swap out Fibre Channel disk to save a buck or two.
"We're characterizing [SATA] as secondary storage, said Steve Gardner, director of product marketing at LSI Logic Storage Systems. Gardner explained that SATA technology doesn't have the I/O performance of FC drives. "On an IOPs basis a SATA drive will produce about a quarter the IOPs as a Fibre Channel drive. The time to data is slow, but once you get there it transfers quickly," he said.
The bottom line, according to Gardener, is that primary applications with high I/O requirements should live on Fibre Channel disks and secondary storage applications like backup and recovery, fixed content and at a remote site for low cost disaster recovery are where SATA fits best.
Gardner cautions users to resist the lure of cheap disk. Business managers are likely to butt heads with IT by saying, why does this Fibre Channel drive cost this much when I can go down to Frye's and buy this SATA drive for less?
"I'm afraid for buyers; it's going to be more complicated to look at what they're getting," Gardner said. "The more sophisticated the IT organization, the better they understand this. People who don't understand the value of serial ATA will experience some unpleasant surprises."
William Saathoff, a senior research and development engineer for CloseLoop Data, purchased two SATA 80-gigabit 7,200 rpm drives from Seagate for installation in a striped RAID configuration. Both drives and one replacement disk have since failed.
"So far, I have lost three hard drives that began with 80 GB to 128 GB to now 160 GB," he said.
Saathoff's server runs a RAID 3 configuration on Windows XP. "It is four months old," he said. "My server lost everything back to the BIOS reload after the drives failed. I am going back to IDE magnetic disk."
Saathoff said his company was attracted to SATA technology because it wanted a server that was new enough that it wouldn't be out of date in two years.
"We believed that we would be able to just swap out the slower SATAs with the faster ones as time progressed. The promise of speed was the main draw," he said.
John Paulsen, Seagate's manager of corporate communications, said failure rates among SATA drives is not unusually high and that there is no known failure issue related to the SATA interface itself.
"Reported problems among SATA drives appear to be fewer than the rate that's typical for ATA drives," Paulsen said.
Let us know what you think about the story; e-mail: Kevin Komiega, News Editor.
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