Dedupe-friendly and ExaGrid

[bteichner]

I just upgraded from Veeam 6.1 to 6.5 last week, and came across the "Dedupe-friendly" setting for the Compression level. We backup to an ExaGrid, and had previously been recommended to not use any compression when backing up to a dedupe device. Is this a new setting that can be used with dedupe devices? And if so, has anyone used this setting with ExaGrid? I was reading through the explanation in the user guide, and it didn't sound like this is what the setting is used for, so I just wanted to get some clarification.

"Dedupe-friendly compression is an optimized compression level for very low CPU usage. It is recommended if the backup proxy does not meet minimum system requirements, and do not want to load it heavily."

Thanks

[tsightler]

Dedupe-friendly compression is really just a rename of the "Low" compression from previous 6.x versions. Interestingly, this compression was the only compression available in early versions of Veeam as it was designed to run on the ESX service console which generally very resource limited. The reason it is "dedupe-friendly" is that it uses a very simple and predictable compression algorithm rather than a complex, dictionary-based algorithm like the other available methods (zlib). This allows it to achieve some minimal compression while still allowing dedupe to be effective at a reduced level.

Typical compression using the "dedupe-friendly" method can be 10-20%, significantly less than the 50-75% (or more) compression available from the other algorithms, however, this will have some negative impact on dedupe, normally reducing it's effectiveness by a similar ratio.

This is primarily useful in cases where bandwidth to the dedupe appliance is limited (1Gb) compared to the amount of data being written. Using low compression means that 10-20% less data has to be sent over the network to the dedupe appliance, which can translate to significant time savings during full backups and VM restores. Some users are willing to trade a slightly lower dedupe ratio to achieve slightly faster backups and restores. If you are currently happy with your setup, I would recommend sticking with no compression.

[bteichner]

Thanks for the explanation. I'll stick with our current setup.

[dellock6]

Brian, I made extensive tests in the past with ExaGrid and Veeam, and I collected the recap of configuration settings in a blog post:
http://www.vuemuer.it/en/?p=3215
settings are still valid for Veeam Backup 6.5. Basically, you can configure veeam with:
- dedup on
- compression off
- alignment off

Luca.