Windows Server 2019 ReFS Deduplication

Hi all,

Windows Server 2019 introduced the ability to dedupe REFS volumes. I’ve seen posts that there’s a flag you have to change in Duplicati for NTFS deduplication, but should I also do this with ReFS dedupe? I’m not concerned if i’m copying too much data up to my Azure Blob storage, I just want to make sure that it didn’t cause any more serious issues.

Thanks in advance for the help!

Interesting that you’d have to do anything with Duplicati with either NTFS or ReFS deduplication. Applications read the data in a rehydrated state. So from Duplicati’s point of view it has no idea deduplication is even being used on the file system (from what I understand).

Look forward to following this thread to get more insight.

1 Like

That’s what I always thought, I’m just paranoid since it’s 5TB of data that I have. It’s a pain for that initial upload to finish if I have to redo it.

I have not tested REFS dedup yes, but it should be same as on NTFS. In all cases, if you use
--symlink-policy=Follow you should be fine in all cases :slight_smile: