WAN accelerator, sizing

[cpfleger]

Hello,

while the Veeam Best Practice guide based on VBR 9.5 U4a states for WAN acceleration that digest files can consume up to 2% of the source disk size
(https://www.veeambp.com/wan_acceleratio ... celeration)

the User Guide based on v10 says one should calculate with 5%
(https://helpcenter.veeam.com/docs/backu ... ml?ver=100)

As this is much of a difference: what is now the correct one?
Or did the new value to be considered here came with v10?

Regards!

[foggy]

The 2% estimation comes from the very beginning, for example, you can see it in v9 user guide and the best practices doc inherited the value as well. At some point, we identified that this estimation didn't take some corner cases into consideration, so it was decided to up the requirement and every version starting Veeam B&R v9.5 requires 5%, so it should be used as the guidance. In most cases, 2% would be enough, but we require 5% to always be on the safe side. Best Practices guide should be updated to reflect the same value.

[cpfleger]

Thx Foggy!!

[Irene L.]

Hi Foggy! May I ask for confirmation as im the one working on BP for WAN accelerators: is it 5% total cause at some point in time there are 2 digest files and we need to count for both, so it makes 5% in total? Did i understand it correctly? Thanks!

[foggy]

Hi Irene, it's 5% of the total amount of source data, regardless of the number of digest files.

[Gostev]

In general, most up to date System Requirements can always be found in the Release Notes, which require 20GB per 1TB of source data. We will need to see why the User Guide ask for much more than that, perhaps this is an old data that was never updated.

[foggy]

5% is a theoretical upper limit, in most cases, 2% is enough but we require those 3% more for safety reasons.

[Gostev]

After checking the actual state with the dev and QC teams behind WAN accelerator, the correct requirements for digests in v10 are as follows:
Low bandwidth: 2% of source disk size
High bandwidth: 1% of source disk size

Please note there were some optimizations in v10 in this department, so the same does not necessarily apply to the previous versions.

So System Requirements in the Release Notes are already correct, while the User Guide will be updated.

[cpfleger]

Thx a lot Anton!!!!