does Veeam Agent backup supports ReFS fast cloning

[dcit]

Does Veeam Agent backup supports ReFS fast cloning?

I have just reformatted volume where is repository which is target for one of our Veeam Agent backup (managed by VBR server) from NTFS to ReFS (before and after I have enabled Windows deduplication). For now I have active full backup on that job (and target of that repo is directory for which deduplication is enabled and that repo saves backups uncompressed).

I am wondering if I should switch to synthetic full backups (and to other repo which has as target directory for which I have disabled deduplication using dedup exception, and does not have checked option to save backups uncompressed). I think that it would have only made sense if that job can use fast cloning, so I am asking this question.

It is somehow choice between dedup and fast cloning as I am aware that combining ReFS fast clone with dedup does not make sense.

Choosing of either of:
d:\Veeam_Backup_Folder (with active backups)
d:\Veeam_Backup_Folder_non-win-dedup (with syntetic backups)

PS C:\Users\Administrator> Get-Dedupvolume | format-list
Volume : D:
...
Enabled : True
UsageType : Backup
...
ExcludeFolder : {\Veeam_Backup_Folder_non-win-dedup}
ExcludeFileType : {vbm}
...


Btw it is on Windows Server 2019 Standard with latest WU.

[Gostev]

Yes, it does. And no, having deduplication enabled does not have any impact on fast cloning. But yes, fast cloning requires that you use synthetic fulls. Thanks

[dcit]

Interesting, I have found here veeam-backup-replication-f2/refs-3-0-an ... 58-30.html that deduplication have impact on fast clone.

I have quoting from it:

Andrew@MSFT wrote: ↑Thu Mar 19, 2020 8:12 pm
This is indeed dedup overhead. In short, if you try to clone a deduped file, dedup will inline-rehydate the file before forwarding the cloning api. This can be expensive, and slow depending on the system...

Also, deduping a cloned file, would increase storage footprint, at least initially, till all the clones have been dehydrated by dedup and their chunks deduplicated.

Did Microsoft changed it? Is it now doing clone without rehydrate?

[Gostev]

No, it was never changed by Microsoft as far as I know.