Veeam B&R NOT reflecting dedupe in UI

[boyjaew]

Greetings,
I have an issue with veeam properly reporting dedupe volume size.

I'm running veeam on a physical box running windows 2012 Standard, dedupe is enabled and working on all windows volumes that hold repositories.
In server manager one volume shows:
Capacity 14TB, free space 4.09TB
6% deduplication rate
and 715GB deduplication savings.

Windows Explorer shows:
4.09TB free of 13.9TB

Veeam shows:
4.2TB free on the repository

A) Should I be bothered by this?
B) What am I missing?
C) Am I just bad at math? Seems like there's 112.64GB that's gone somewhere between what windows sees and what veeam sees.

Side-note - in the time it's taken me to compose this, veeam has apparently changed its mind. It now reports 4.1TB free on the repository in question...

I'll be damned. Apparently they just synched up. In any case if someone feels like explaining this I'd still like to hear it so that I might be able to explain it to my cohorts.

Thanks!

[Vitaliy S.]

Hello JB,

That's actually interesting behavior...what happens if you do a "rescan" action on your repository server? Do you see updated numbers?

Thank you!

[boyjaew]

Thanks for the reply -

Just rescanned all repositories.

Now a different repository is doing the same thing.

server manager = 5.07TB free
windows explorer = 5.07TB free
veeam = 5.1TB free

But, I bet if I watch it long enough, they will synch up. Rescan did not change anything in this case.

[Vitaliy S.]

Our inventory maintenance job is triggered every 24 hours, so doing a rescan should force the update of the infrastructure components. I don't have any Windows 2012 repositories handy, but could it be just a round-up issue?

[boyjaew]

That's kinda what it looks like to me. Plus, veeam doesn't show the next decimal place, but it's closes enough. For what it's worth after the rescan there doesn't seem to be the same latency between the windows and veeam stats. Could just be me being impatient. I did notice that before when we had this issue there was always a discrepancy between windows and veeam, but I have since enabled "Align backup file data blocks" and "Decompress backup data blocks before storing" under repository>advanced. Now they seem to track pretty closely to one another.

[Vitaliy S.]

I have since enabled "Align backup file data blocks" and "Decompress backup data blocks before storing" under repository>advanced. Now they seem to track pretty closely to one another.

I doubt these settings influence free space calculation logic, it should be about just querying target storage for space utilization.

[boyjaew]

Thanks, good to know. Side note, it seems like the processing rate of last night's jobs were improved with these settings enabled. Does that make sense or just a coincidence?

[Vitaliy S.]

"Decompressing backup data blocks before storing" option can improve the dedupe ratio on your device. As to the second option about the blocks, then in some cases it is not recommended to enable it for dedupe devices > Recommended settings when using a dedupe appliance

[boyjaew]

Something I've not been quite clear about. Is server 2012 dedupe feature considered a "dedupe device" in this case?

[Gostev]

Yes, most definitely it is.

[boyjaew]

Excellent! Thanks for all the help, people.

[veremin]

It might be worth taking a look at the adjacent thread about using Windows 2012 dedupe repository; useful tips and tricks can be found there. Thanks.