The Backup Blog

Inside Avamar: Fast NAS and NDMP Backup

Last time out, we went over the reasons why Avamar is different and faster than other backup applications for backing up unstructured data sets.

This time out, I thought we should turn our attention to NAS (filer) backup under Avamar. Again, we see big differences in how Avamar handles NDMP backups. Again, we see that Avamar backups can take only 10% of the time of a standard NDMP backup. But it turns out that the reasons for this are totally different than the reasons that Avamar is so fast at unstructured data backups.

First, a bit of background. Avamar doesn't really do full or incremental backups. Avamar does a backup. That backup data is written together with existing backup data on an Avamar server in a way that a full system image is present for every day on which a backup occurred.

Inside Avamar: Fast Backup and Finding Backup Candidates

Last time out, we talked about Avamar's global client deduplication. This time, I want to go into some more depth on what makes Avamar so fast for some types of backups.
 
Saying something is "fast" is always a bit subjective. I know that some things like Lamborghinis are fast. I know that Valentino Rossi is fast. But how fast is Avamar?
 
On average, Avamar is about 90% faster than most other backup products to make a backup of an unstructured data set. And in backup, speed matters. In fact, I would argue that it is the most important thing a backup application or platform can offer. So finding a solution that lets you cut backup times by 90% is important. And in some cases, it is crucial. For platforms and infrastructure that have expreienced 24+ hour backup windows, this is a decisive factor.
 
How does Avamar do it? Well, Avamar has a pretty elegant way to reduce the amount of time that it takes to determine what needs to be backed up.

Inside Avamar: Global Client Deduplication

I spend a lot of time talking to people about Avamar. I think it is a great application that pretty radically reinvents backup architectures. It does so many things well, and has consistently been ahead of the curve in terms of delivering advanced backup technologies. For example, Avamar was one of the first to market with a true disk based deduplication solution for backup.
 
And often I tell people that Avamar's overt association with deduplication is one of its' challenges too—in the sense that Avamar actually does two things at the client level that are really important. It is not just deduplication, but the duration and resource utilization of the Avamar client that are so impressive. Not only does deduplication reduce the amount of data to be backed up by 99% or more in many cases, but the duration of an Avamar backup is usually 90% less than the duration of a standard backup. To those of us that are concerned about growing amount of data and the impact on backup windows, this is a fundamentally important characteristic, and one that is, in my opinion, just as important as deduplication itself. (And one that I will discuss in a follow up post.)

EMC World 2011 BRS Conent Online

All content from the EMC World 2011 BRS Sessions is now online.

Below is a list of all the BRS sessions from EMC World 2011 with links directly to the content, which include PowerPoint and audio recordings of the sessions. Enjoy! If you want to see more in-depth descriptions of the content, as well as the level and duration of the content, please find an expanded version of EMC World 2011 BRS Content here.

Tape and Deduplication

I just saw an interesting article by Chris Mellor over at The Register. Chris was speculating on why we haven't seen any deduplicated backup on tape. Because, hey, if I can squeeze 20 times as much data on a disk using deduplication technology, doing so on tape has to be a good thing, right?

And it would allow tape vendors to show that the technology has some relevance beyond long term archiving.

Chris has a lot of good explanations as to why we don't have dedup on tape yet—except from CommVault and EMC. But he misses the biggest reason of all: it might be really good for backup, but it is horrible beyond belief when it comes to restore. And as myself, David Chapa, and every other backup specialist will tell you, it is all about restore.

Why is it so terrible? Seek time.