Win2012 dedup volumes query

[briggs]

Hi,
We've experimented briefly with Win2012 dedup, and it seems the way forward for us, enabling it undoubtably saves us a fairly large percentage of disk space (35%+)
My question is, if and when we migrate to Win2012 for our file and print servers, we'll still be backing up with Veeam of course. But are there any implications with regards to restoring the disks and or the guest files of dedup volumes? Is there anything I should know? Will veeam backup the server in its dedup state (ie smaller backups) or will it ignore the dedup?
Just after a bit of insight please, it's really the key selling point for us, so I need to fully understand the reality before I spend the companies money on it all!
Many thanks, Alan

[foggy]

But are there any implications with regards to restoring the disks and or the guest files of dedup volumes?

To restore files from deduplicated volumes, backup server must be installed on Windows Server 2012 with Data Deduplication feature enabled in the OS settings (this is mentioned in the release notes document).

Will veeam backup the server in its dedup state (ie smaller backups) or will it ignore the dedup?

Veeam B&R is an image-level solution, so it will backup the VM image in its actual (deduped) state. Note that despite the smaller amount of data inside the guest, data deduplication technology produces considerable amount of changed blocks, so expect large increments for such VMs.

[briggs]

Thanks for that.
Your comment about large increments, just how large are we talking? Do you think with the smaller initial full (as it's dedup'ed) would offset the bigger size of the incrementals? We do Mon-Fri twice-daily backups, for a month, before then next full (so at least 40 incrementals exist), so if I end up with much bigger incrementals, my backup storage might run out of disk space! There's always a downside to everything Grrrrr

[foggy]

I guess it depends on such factors as the amount of actual data, how well they dedupe, amount of changes produced by VM, etc. You can test to see what increments will look like in your case.

[mwiseley]

Our main file server is Windows server 2012 and we use the built in Server deduplication on the volumes. This works great, however when I back it up using Veeam, my 2 TB of data become 4 TB. This is confusing to me as Veeam is supposed to be doing deduplication as well and while I understand it would not be able to deduplicate the data more it does seem odd that the data almost doubles when going to the backup. Are there special settings that I should use for the backup? Has anyone else experienced this? I'm using inline deduplication, optimal Compression and Local Target for Optimizations.

Thanks,
Mark

[foggy]

Mark, most likely this is caused by large number of "dirty" blocks (unused by the OS but not zeroed due to how NTFS works, as deleting the data in NTFS does not actually touch the content of the corresponding blocks), which are copied during backup.

[briggs]

Mark, I really didn't want to hear that! We're planning a 2012 migration for this year, the main reason being the dedup feature to help us out with our ever growing file servers.
I really can't afford to save space on the SAN, but end up with bigger backups!
Can you tell me if the 2TB of data is deduped more than 50%? ie. if you had no OS dedup, would the backup of been 4TB anyway? Or are the backups bigger than they would of been on a 2008 server say?
What about incrementals, are they suffering the same jump in size of 50%?
There's always something to spoil the party

Thanks,
Alan

[foggy]

I really can't afford to save space on the SAN, but end up with bigger backups!

You have to be ready for large increments in this case, since deduplication works inside the guest seriously affecting the number of changed blocks, while Veeam B&R works on the virtual disk level and has to copy all those changed blocks.

[briggs]

Do we know how large? Is there any sort of calculations to be done? It's making me very nervous, maybe I should of kept Arcserve (tongue in cheek )

[veremin]

Do we know how large?

No, we don't, as it varies dramatically. So, only the actual tests are likely to clarify it for you. Thanks.

[mwiseley]

Mark, I really didn't want to hear that! We're planning a 2012 migration for this year, the main reason being the dedup feature to help us out with our ever growing file servers.
I really can't afford to save space on the SAN, but end up with bigger backups!
Can you tell me if the 2TB of data is deduped more than 50%? ie. if you had no OS dedup, would the backup of been 4TB anyway? Or are the backups bigger than they would of been on a 2008 server say?
What about incrementals, are they suffering the same jump in size of 50%?
There's always something to spoil the party

Thanks,
Alan

So... our incremental backups are using between 20-40 Gigs each and we are doing a backup daily. Not too bad considering how large the drives are.
As for our deduplication rate on the File server, we have multiple drives and here are the rates,
26% - Small file share
48% - Main Office share of documents
27% - Images and backups
29% - Home directories
41% - Software
30% - Production file share

Also we are a heavy pdf shop so that probably brings our office and production share rates down a bit as pdf's do not dedupe very well.

As for the size if we had not deduped, well I don't know that one as we have never backed it up with Veeam prior to the deduplication. We were using SAN snapshot and replication.

[dcarey]

This is what we've been seeing. The dedupe process seems to generate more cbt our users generate on a daily basis. Be interested to know what others are doing as I'm on the verge of turning off dedupe for this very reason and going old skool.

[B&R]

Hello,

Are there any considerations / remarks / useful things to know when backing up Windows Server 2012 R2 deduped volumes? Our storage is first a direct attached 16-disk array and after that an HP StoreOnce shelve.

[B&R]

A specific question that comes to mind: If i start a restore job 'Guest files (Windows)', will I be able to copy files from the deduped volume to another server?

[veremin]

Yes, as long as backup server has Deduplication role enabled. Thanks.