In these cases, the backup session would include three processes: transferring data to the on-site backup device, deduplicating that data set and then replicating it to an offsite location. Depending upon the technology used, the dedupe process may be done before, during or after the time that data’s transferred to the on-site backup device. But data replication always comes last, and the methods a backup vendor uses to integrate these three processes is key.

Some backup vendors essentially have to wait until the entire dedupe process is done before starting data replication. Others can replicate out of the “back end” of the dedupe engine while new data is still coming into the “front end.” The challenge lies in deduplication technology itself, and the fact that many vendors don’t have a simple way to break this complex process up into smaller pieces, so it can be run concurrently with replication. When this happens, the wall clock time on the backup session can stretch way beyond the backup window that’s been established. While this won’t always disrupt other IT operations, it does mean that an organization’s data isn’t safe. In the worst cases, another backup session may actually begin before the previous one is complete.

As a VAR, you’ve probably got more than one vendor offering deduplication as a part of its backup solution. And, you’ll certainly compete with others in the deals you run. Many vendors define “backup window” and the time their products take to complete a backup session very differently. It would make sense to understand exactly how your vendor does these steps, how long it really takes for the whole backup session (wall clock time) and the claims they make about their performance. The ‘devil’s in the details’ and you need those details in order to educate your customers and best present your solutions.

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