USB stick vs. harddrive / Backup and Restore

System: PC, Windows Server 2019, Roon Core

Wanted to report a solved problem as it might help others:

I had set up a new computer, moved the core and wasn’t able to restore the database backup from a USB stick. Roon did not find anything, neither on the stick nor after copying the backup to the internal harddrive.

I have then copied the same backup from the old machine to an external USB-harddrive and this copy of my backup was directly found by Roon and got restored onto the new machine.

Two learnings here:
A. Two Backups: I was lucky that I had made two backups before migration, one directly to the USB stick and another one directly to the internal harddrive of the old computer
B. Fallback: I have heard of the advise to never copy backups but to make them from Roon directly to the external drive. Maybe that’s correct but in my case it failed. However, never ever clean the old system or delete the backup source before the backup has been successfully restored to the new system. I know, that’s really Computer ABC, but some people seem to have run into lost databases on this forum.

Idea: Maybe Roon should check the backup before completion as to whether or not it can be restored later. I am not sure this is fixed or really controlled.

Of course, both sources / folders (USB stick and external/internal harddrive) look exactly the same, one can be restored, the other one can’t.