I got the same issue with a db file of 273GB and i found this plex bug that i though may be the culprit. (Although i dont have beta release channel checked) https://forums.plex.tv/t/library-db-size-more-than-doubled-in-latest-version/918851/324 But after doing their recommended fix (pressing optimize the database in webui, which took 36hours (during which plex is unresponsive)) it is still 262GB. I intend to dig into that db file to see whats taking all the space later. You can see if optimize works for you, but be aware that it will first double the size used before removing it at the end. When plex is responsive again it is done and you’ll need to restart the docker to let it clear the db wall file. If you don’t care about your watch history then i am pretty sure you can also delete the database files.