- Shut down Plex server
- Revert to a database backup from before the drive switch over: https://support.plex.tv/articles/202485658-restore-a-database-backed-up-via-scheduled-tasks/
- swap the drive letters of the original drive with that of the backup drive in the Windows control panel Change a drive letter | Microsoft Learn
- verify that all the folder names on the backup drive are identical to the origianl drive. If not, make them so.
- start Plex server
Due to points 3 and 4, Plex shouldn’t even notice that something has changed.
The whole approach will probably only work if there weren’t other Plex libraries on the same drive(s).
The alternative to the above would be to change the drive letters and folder names directly in the server database, which is something only someone well versed in SQL should even attempt. [HowTo] Plex database modification - Moving media the right/wrong way - #10 by jelwell
