CDP jackpot

01.09.2005
Von Mario Apicella

One of the questions I am asked most often is how I choose what to write about each week. Well, that question is rather difficult to answer, but let me try a metaphor: It"s similar to playing a slot machine in Las Vegas -- to win big, you have to line up three good symbols, like three cherries or three bells.

This week, three cherries lined up for one of the most often whispered, shouted, or just pronounced acronyms: CDP, or continuous data protection.

CDP is the logical equivalent to having a full umbrella protecting your company data, as opposed to the partial umbrella offered by your typical backup application.

Think about how many times a day you run backups of your most critical data. Once a day is good; more frequently, excellent. Regardless, the next question is what you"re supposed to do if something of a catastrophic nature destroys your data between backups.

Of course you can start with a restore from the latest backup, but that could bring back data that is hours, or possibly even days, too old. Do your users know that in your data-protection scheme they may have to manually fill that gap? More important, will they be able to retrace all the updates since the last backup?

As unbelievable as it may seem, what I just described is an all-too-common situation in far too many companies, including yours and mine. Perhaps even more stunning, the big software vendors (those that sell you backup applications) have failed to realize for a long time that the time was ripe to move away from the partial protection offered by that approach.

In fact, you"ve probably heard of CDP (or near-CDP) products from sources such as StorageTek, XOSoft, or Microsoft, but never from a backup vendor -- at least until now.

IBM was the first to break away from the crowd, announcing an application that promises a full data-protection umbrella, at least for users" files. The name is excruciatingly accurate: " IBM Tivoli Continuous Data Protection for Files," which should remove any doubts about using it for anything BUT files.

"Any place in the value chain, any place where files are being created, you can add this product," explains Chris Stakutis, CTO and creator of IBM Tivoli CDP for Files. He adds that after installing the product, every time a file is saved a copy is captured and saved to a local pool.

"Optionally, the file is also queued for transmission to an off machine," Stakutis adds. "And lastly, there is an element of scheduled protection in the product as well."

I thought to myself that it sounded too good and too easy to be true, and I couldn"t resist taking an early peek at the product and installing it on my laptop. After using it only a few hours, I am sold on the idea.

Explaining in detail how the product works will probably take more space than I am afforded here, but you can essentially choose which drives and directories you want protected and which ones you want to ignore, then you set your external target to any file server or mapped volume you can write to.

It sports great simplicity and ease of use, but the best part of CDP is that restores don"t require mounting a tape or a CD or bribing your IT manager: You just do it yourself. I have a rather sophisticated set of scripts that take automatic daily incremental and quarterly full backups of my laptop, but I am going to add CDP to that setup permanently.

At only US$35 per machine, it"s affordable even if your employer won"t pay for it, and it makes me feel fully protected for the first time. (A server license is a bit more expensive, at $995.)

Perhaps you"re still wondering how I choose my column subjects. Sorry, can"t tell. What happens in Vegas stays in Vegas.

Join me on The Storage Network blog to discuss this and other topics.