Hello!! 
This is my environment:
- Nextcloud 17.0.1 server [Linux machine]
- Windows Server 2019 with shared folder.
I have configured the Windows shared folder in Nextcloud as a “external storage” with SMB/CIFS protocol and apparently it works fine.
The shared folder in Windows Server is in volume that has deduplication enabled.
The volume has VSS enabled, too (file and folder versions enabled in Windows volume).
This is the question:
Nextcloud is 100% compatible with shared folder (external storage) whit deduplication and VSS enabled?
In the past I read about this topic and I found references indicating problems with corruption data.
At present, is this environment reliable?
Or is it recommended not to use neither deduplication nor VSS?
Best regards.
Fran.