Beware the IDEs of disk

Sweet spot between tape and RAID

The enterprise storage industry could not ignore IDE for much longer. At the low end, IDE-based RAID boxes now beat SCSI hands down on price per MB, and with many drive manufacturers making their SCSI and IDE products from common components, the argument that SCSI offers better quality doesn't wash anymore.

What SCSI does though, is offer more performance and the ability to connect more drives to a controller, at least until Serial ATA becomes commercially available. So what roles does that leave open for IDE in the enterprise?

Quantum's latest answer is to pack a stack of IDE disks into a box which emulates a tape library. The idea is that backups can then be written faster, after which the application server can get back to work while the tape images are copied onto real tapes in the background.

If you think you have heard this story before, you are right. The DX30 backup array was actually announced back in March, but early adopters blew Quantum a raspberry, saying that version was too slow. So now it has a new model, with a faster controller, enhanced software and higher capacity - up to 3TB when fully populated, with 10 to 15TB models on the way.

The improvements make the box three times faster than tape, where the first version was only twice as quick, says David Kenyon, the product line manager at Quantum's storage solutions group. The DX30 also makes file restores faster, because in most cases the file needed will still be on disk, with no need to load a tape.

Network Appliance too has a box chock-full of IDE disks, which it calls NearStore and describes as near-line storage. NetApp suggests that data which needs to be online but doesn't need the performance of a high-end NAS filer can be placed on here instead.

NetApp CEO Dan Warmenhoven says that it could be cost-effective in data replication and disaster recovery, where most of the time the second copy is merely a redundant image of the first. "We can replicate from high-cost to low-cost storage because of the software compatibility across our range," he adds.

Whether either will fly is another matter. Kenyon admits that people are still delaying storage purchases right now, but says that unlike its predecessor, this DX30 will be an economical and simple way to speed up backups. "There is a sweetspot between tape and RAID," he says. "The only difference is we approach it from the tape side, where NetApp comes from disk." ®

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