Expected Deduplication Behaviour

[amosperrins]

In our organisation we've got a few large, monolithic virtual servers that host multiple services and we're thinking of farming these services out to separate servers (e.g. IIS & RDS currently on the same VM). The worry is that backups will inflate as a result of these and my initial testing seems to support that:

I created 2 identical Server 2012 R2 VMs from a template, left them powered off and performed a full backup with Extreme compression, WAN target deduplication & per-VM chains left disabled. What I'm seeing is that the resulting .vbk is twice the size of single VM backup (~8GB) when I back both VMs up (~16GB). This is onto a plain old NTFS RAID-10 volume with MS dedupe disabled.

Am I expecting too much for Veeam to be able to dedupe an entire VM? Have I understood Veeam dedupe correctly?

Any help would be much appreciated, thanks!

[DGrinev]

Hi Richard and welcome to the community!

Please share the dedup ratio and other stats from the job session.
You can find out how to generate the report by following this link. Thanks!

[foggy]

A stupid question, inline deduplication is enabled in the job settings, right?

[amosperrins]

Thanks for the replies, folks.

A stupid question, inline deduplication is enabled in the job settings, right?

'Enable inline data deduplication' tick box is definitely ticked (though I did have to triple-check for my own sanity).

Hi Richard and welcome to the community!

Please share the dedup ratio and other stats from the job session.
You can find out how to generate the report by following this link. Thanks!

With one VM:


With both VMs:


Given that TEST1 & TEST2 are identical, shouldn't there be a higher dedupe ratio on the second active full containing both VMs? Thanks again!

[DGrinev]

Richard, I have no access to the images you've posted.
Please share them using any free hosting like https://imgur.com/. Thanks!

[amosperrins]

Sorry about that, these links should work:

[DGrinev]

Richard,

Is there any chance the data encryption enabled?
Please can you check and share the size of the .vbk files in the repository. Thanks!

[amosperrins]

Hi Dmitry,

The .vbk files are the same size on the repo as detailed in the report - our repo is pretty vanilla.

Regarding encryption, it is enabled on the job - when disabled I see the expected dedupe ratio (up from 4.5x to 9x). Is there any way to have dedupe & encryption enabled simultaneously?

Thanks again for your time, I appreciate it.

[DGrinev]

Hi,

Unfortunately, there is no way to combine encryption and higher deduplication ratio. Thanks!

[amosperrins]

No worries, thanks for your help!