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Full Name: Adrian Hinton

Possible Server 2012 Deduplication Limitations

Post by AdrianHinton »


I have a backup job of 1.4TB and the VM is currently 995GB due to some disks being removed since the backup job was created. The Copy job sends these copies to Windows server 2012 R2 to a dedup volume that is a total of 7.3TB in size.

Below is from "http://msdn.microsoft.com/en-us/library ... s.85).aspx"

Deduplication is not supported on:
System or boot volumes
Remote mapped or remote mounted drives
Cluster shared volume file system (CSVFS) for non-VDI workloads or any workloads on Windows Server 2012
Files approaching or larger than 1 TB in size.
Volumes approaching or larger than 64 TB in size.

Am I correct in assuming that at least one VBK in this job would be approaching 1TB in size even with the dedup enabled? And if so, should I not be using deduplication for this job?

Vitaliy S.
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Full Name: Vitaliy Safarov

Re: Possible Server 2012 Deduplication Limitations

Post by Vitaliy S. »

Hello Adrian,

I believe the reason why Microsoft stated that it is not supported comes from this behavior. As to the question about not using deduplication for the job, then you do need to use it no matter what target repository is used.

If you have large backup files, then splitting the backup jobs can help you to workaround the limitation you have referenced above.

Thank you!

Veeam Software
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Full Name: Alexander Fogelson

Re: Possible Server 2012 Deduplication Limitations

Post by foggy »

That said, if the data size is currently 995GB, with compression and deduplication enabled in the job settings, VBK size should not exceed 0.5TB (we usually take 50% as the worst for data reduction). What is the size of the backup copy VBK currently? You could probably perform a compact operation over it and get an acceptable size for Windows dedupe.

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