I’ve often stated that tape is still cheaper than disk, even after dedupe. I know that many dedupe salespeople try to tell customers that they’re going to save money by moving from tape to their wonderful deduped disk system; I just don’t see how that is possible. I’m absolutely convinced that tape is still cheaper, for a lot of reasons. The only question is how much cheaper?
The big reason this is true is that almost no one is getting rid of their tape drives. While some companies absolutely have, some customers that have tried have stopped trying. They find it impossible to meet the long term storage requirements of backups and archives, and — much worse — legal hold requirements, without being able to make a pile of tapes and set them on a shelf somewhere. This means that almost everyone is still keeping at least some of their tape drives.
So if you’re not getting rid of your tape, and instead buying one (or more) additional appliance(s), each of which is going to cost far more in power and cooling than the tape system you’re not getting rid of of, and neither of which is completely self-managing, how is it that you’re saving money again? You’re tripling the size of your infrastructure, and 2/3 of that tripling is going to be disk that is more expensive than what you already had. And if you’re going to be replicating your backups, you may need bandwidth you never needed before. That bandwidth isn’t free.
But that actually wasn’t what I was going to be writing here. Deduped disk has gotten so hot that some companies are charging way too much for it. I recently saw a price comparison between a tape unit and a deduped unit where the tape unit was about $6,000 and the equivalent disk unit was $200,000. WOW.
Is the deduped disk unit easier to use? Absolutely. Does it enable onsite and offsite backups without touching tape? You bethcha. Would I rather have my backups on disk rather than tape if I had to do a lot of restores? Definitely.
But is it cheaper? I don’t think so. And that’s all I wanted to say.
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Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Evangelist at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.