SOLVED: Migrated to Docker: can't scan libraries?

[dataprolet]

I migrated my Jellyfin installation on Arch Linux to a Docker container on Debian according to the official instructions. I created a colume for /config and one for /cache as well as bind mounted my media drive to /config/data/media. Everything seemed to work out-of-the-box. My user accounts, plugins and library were all showing up. I can watch all my latest media as if nothing ever happened.
But I can't scan my libraries! The scheduled task failed and when I try to manually scan my existing libraries the window seems to break and simply shows a black screen and the top menu bar.
When I right-click my library listed under "My Media" and select "Edit metadata" it shows a wrong path (/var/lib/jellyfin/root/default/media). I already tried to edit this in the library.db, but then all my media disappeared from the Dashboard.
What am I missing or doing wrong? How come I can play my media but not scan the library?
I also get constant error logs like the following:

Code:

[17:24:20] [INF] [8] Jellyfin.Api.Auth.CustomAuthenticationHandler: CustomAuthentication was not authenticated. Failure message: Invalid token.
[17:24:20] [INF] [8] Jellyfin.Api.Auth.CustomAuthenticationHandler: AuthenticationScheme: CustomAuthentication was challenged.

[TheDreadPirate]

Switch the bind mount for your media to a volume. I'm not expert enough to explain why, but bind mounts introduce some complications that require extra configuration to get everything to work correctly. Its easier to just mount your media as a volume.

Those token errors may be related to your migration. Your clients may be using cached tokens for authentication that may not be valid anymore. Or something like that.

[dataprolet]

Thank, but how do I add existing data to a Docker container using a volume? I have several TB of media files, that I really don't want to copy into a volume.

[TheDreadPirate]

Volumes don't get copied. You are mapping a host directory to a directory in the container.

Code:

--volume /path/to/media/on/host:/media

Or, if using docker compose

Code:

volumes:
      - /path/to/media/on/host:/media

Within the container /media is mapped to wherever you have your media on the host. No copying is done.

[dataprolet]

That does seem to work, but only when I re-add the libraries in Jellyfin. But then Jellyfin is also scanning everything again..

[TheDreadPirate]

If you mounted it to the same path as before it should have been transparent. /media was just an example. Well, as long as it works now...

[dataprolet]

I did the re-scan and everything looks and feels as before. Thanks a lot, easier than I thought.
The auth error apparently also disappeared.