How Much Are You Really Saving With Traditional Deduplication Appliances?

By Dipesh Patel

People often get obsessed with dedupe ratios and dedupe technologies, and have a hard time seeing the "big picture" around how much they're really going to save. Let's compare the savings from the traditional target-based dedupe vendors (like Data Domain, among many others) against standard commodity disk-based storage. I purposely left CommVault out of this and put myself in the shoes of an IT shop evaluating deduplication as a whole versus the "next best alternative" which is simply to use generic off-the-shelf storage. It also helps minimize any accusations that I'm unfairly manipulating the CommVault pricing just to make us look good.

To start, many traditional target device-based deduplication vendors often tout data reductions in the range of 10:1 to 20:1. So, let's be conservative and use 10:1 as a dedupe ratio to see what that really amounts to in dollars saved.

So, if you are backing up 100TBs of raw data, then with a 10:1 reduction, you're storing 10TBs on the target deduplication device. This sounds great because you're saving 90TBs of disk capacity. On the other hand, if you choose not to de-duplicate the data, then you'll end up with something like 50TB on regular commodity disk (on average, assuming you still compress the data).