Quantum shrinks disk backups

As we get closer to SNW (Storage Networking World) Spring, it's worth taking a step back and preparing ourselves mentally, so to speak, for the show.

Judging from the vendors' frenzy to secure a hearing with the press -- "I only need 20 minutes" is one of the classic pickup lines -- this year's SNW promises to be another interesting show. We'll see many new solutions; on the other side of the coin, we'll have to listen to lots of hype.

Telling one from the other isn't always easy and may depend on your specific business requirements and the stuff you've already deployed. To paraphrase an old saying, "One man's hype is another man's treasure." For example, if you are still struggling to build an ironclad data-protection system, all the talk about ILM (information lifecycle management) may not hit home -- but new approaches to backup and restore probably will.

The good news is that SNW will have lots to show on data protection, because it's an area where, to put it nicely, there is still considerable room for improvement.

One major preshow novelty comes from Quantum, which just announced new models of its DX30 and DX100 VTL (virtual tape library) appliances, bringing hardware-based compression to disk-staged backups. As far as I know, it's a first.

Hardware compression is a popular option when backing up to tape, because it shrinks data to about half its normal size, saving backup time and making for a more efficient use of the tape medium. To complete that picture, many (I should probably say all) backup applications can compress data on the fly during backups, but it's a rarely used feature because compression puts an additional burden on the servers' CPU and lengthens the backup time.

As a consequence, data compression had all but disappeared from the disk-staged backup space. Quantum's new DX models bring it back in style with in-line compression automatically done for the whole appliance.

Assuming an average 2:1 compression ratio, Quantum estimates that with a typical RAID 5 setting, a fully configured DX30 squeezes in about 26TB of backups, whereas the larger DX100 stores four times that amount.

It's undeniable that customers will be able to store more data with the DX line, but will compression make backups slower? No, because the additional silicon in the DX units grants seamless compression, says David Garcia, product line manager of the DX-Series. According to Garcia, customers will also have an easier task migrating already-compressed backups to tape and estimating how many cartridges the backups will occupy.

I can't resist asking if Quantum is considering hardware-based encryption on its DX line, but neither Garcia nor Shane Jackson, director of Quantum enterprise product marketing, are ready to discuss that topic.

However, the mid-March DX announcement offers plenty to discuss already, because the new models -- which should begin shipping in April -- offer the ability to create multiple VTLs. That should be of interest to customers who need to maintain separate operations, such as between different departments or different faculties on the same campus.

According to Garcia, the two DX models will also reach optimal performance with a new allocation algorithm that automatically spreads the load across multiple LUNs (logical unit numbers).

Obviously, data compression is the main scoop of this announcement from Quantum, because the new appliances have double the capacity of previous models. Jackson says existing customers can update their units to take advantage of the increased backup space.

That option could be a lifesaver if you're running out of space on your appliance, and it may open an interesting debate about what's more effective in dealing with storage limitations, adding more disks or getting the compression update.

While you ponder that, also keep in mind that neither Garcia nor Jackson mentioned ILM once during our discussion, and I wasn't a bit unhappy about that.

Mario Apicella is a senior analyst at the InfoWorld Test Center.

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