Roon loses connection to mounted external USB drive on Synology NAS

My Synology DS720+ is slowly running out of space, so I added an external USB drive and moved the most storage-intensive music files — the DSF files — over there.

I added the folder as a storage location in Roon, but… every few minutes Roon loses connection to the mounted folder, then reconnects, then loses it again.

On my Mac, I can browse the DSF folder the whole time without interruption, and the Synology interface shows no issues either — yet the folder keeps disappearing for Roon.

That’s not great, especially when trying to identify new albums, which suddenly appear as deleted, etc.

Is there anything specific to consider on the NAS side when mounting folders from external drives?

Has anyone experienced this issue and found a solution?

Those external drives are probably sleeping. Your are better off upgrading the drives in your NAS.

Mac and Synology maybe using cached folder lists? In the ‘disappeared state’ Can you start playback from Mac for any of the files to see if access is actually possible. If it is (without delay) then Roon has an issue.
If the drive was asleep there should be a small delay before Synology wakes it up, then everything should work normally. Drive sleeping behaviour can sometimes be fixed using tools provided by the drive manufacturer.