Server Version#: PlexMediaServer-1.43.1.10576-06378bdcd-x86_64_DSM72
Player Version#: 4.159.0
Hi, my music library is around 1,3 TB with about 225.000 files.
I just noticed that my Plex Media Server tmp folder is stuffed with folders named "like “music-analysis-input-d63f4a55-5a2a-4470-bc75-a9ff15a3f1ea” and contains in total 4,59 TB with over 714.000 files (see screenshots).
The music library is the only library that uses “Sonic Analysis”, but I cannot understand why the tmp-Folder got so big? It is currently using up almost 12% of my entire NAS, just for the Sonic Analysis temp-files?
Any idea how to dig deeper or - even better - how to resolve this?
If your screenshot is showing all the folders, I think there is a disparity between the number of folders and the number of files within.
You see, the sonic analysis is processing all tracks within one album at a time.
If there are relatively few folders, but with thousands of files within them, I think that you must have a few albums with an unreasonably high number of tracks in them.
It might be that the analysis process has hit a timeout while attempting to perform the sonic analysis on these few ginormous albums and has left the temporarily decoded files behind for some reason. (you can even listen to them, they should be in WAV format)
I think it is safe to delete all those folders which are older than 48 hours manually. You may want to temporarily shut down the Plex server process on your NAS before doing so.
While you’re at it, you can delete the PlexCreditsDetection folders as well.
You should go on the hunt for these behemoth albums and remove them.
Their purpose is better served by playlists or collections in Plex.
Some of the folders contain about 27.000 wav-Files.
I just checked via TreeSize, the biggest album is a “1001 songs before you die” album, followed by a box set with 12 CD which in total contain 987 tracks, otherwise I have many “Top 100 Charts of [year]” albums.
Alone the “music-analysis-input”-folder of today contains now almost 20.000 wav-files (adding about 60 per minute currently) with tracks from “normal” albums containing only about 10-20 tracks.
At the same time my “Sonic Analysis” is stuck since yesterday at 120 albums.
Dunno if it related, but it feels like the Sonic Analysis wants to transform EVERY song I have to wav format.
The “Plex Media Server” log seems to report mainly stuff like:
“Jun 05, 2026 14:19:26.740 [139967919602488] DEBUG - [MusicAnalysis/JobRunner] In directory: “/var/packages/PlexMediaServer/shares/PlexMediaServer/AppData/tmp/music-analysis-input-6b4f85a9-6dbd-4a0a-b05f-32e628a969af”
Jun 05, 2026 14:19:26.740 [139967919602488] DEBUG - [MusicAnalysis/JobRunner] Jobs: Starting child process with pid 13055
Jun 05, 2026 14:19:27.968 [139968485391160] DEBUG - Jobs: ‘/volume1/@appstore/PlexMediaServer/Plex Transcoder’ exit code for process 13047 is 0 (success)
Jun 05, 2026 14:19:27.968 [139967921711928] DEBUG - [MusicAnalysis/JobRunner] Job running: FFMPEG_EXTERNAL_LIBS=‘/var/packages/PlexMediaServer/shares/PlexMediaServer/AppData/Plex\ Media\ Server/Codecs/c75335c-a7cfb6836f3ed63280a7eb83-linux-x86_64/’ “/volume1/@appstore/PlexMediaServer/Plex Transcoder” -i “/volume1/MEDIEN/Audio/Musik/Electronic/Various/V.A. - Bleep - A Guide to Electronic Music (2012)/52 - Burial - Raver Archangel.mp3” -ac 1 -ar 16000 -acodec pcm_s16le track-19552.wav
Jun 05, 2026 14:19:27.968 [139967921711928] DEBUG - [MusicAnalysis/JobRunner] In directory: “/var/packages/PlexMediaServer/shares/PlexMediaServer/AppData/tmp/music-analysis-input-6b4f85a9-6dbd-4a0a-b05f-32e628a969af”
Jun 05, 2026 14:19:27.968 [139967921711928] DEBUG - [MusicAnalysis/JobRunner] Jobs: Starting child process with pid 13071”
It looks in the logs like most of the songs processing are from compilations, though the albums itself have a reasonable amount of tracks (though the album artist “Various” in the mp3-metadata has a very high count of course)
Which of these folders has been added to your music library?
I think it must be neither /Audio, nor /Musik.
Instead, it should be /Electronic (together with all the other genre folders you might have beside it. Be advised that this might only be practical if your number of genre folders is a few dozen, but not more).
This is to make the folder structure, which is exposed to the Plex scanner, conforming to https://support.plex.tv/articles/200265296-adding-music-media-from-folders/
It might help to avoid the above issue as well.
Within “Musik”, there are currently 18 genre-based sub-folders containing the “artist - album” folders.
Could this already cause such a mess?
I am currently in the process of cleaning up the metadata, all compilation albums should already have clean metadata (with “Various” as album artist), but maybe I have missed something somehwere.
Possibly, particularly if the embedded meta tags are not complete. (Albumartist is of particular importance in Plex.)
Plus, there are so many artists which were/are active in several genres. I think that a hard genre separation above the artist level inevitably will be incorrect in many cases.
I recommend to use the more verbose “Various Artists” instead – at least in the embedded Album Artist metatags.
This artist is treated specially in Plex and Plexamp.
Very interesting, can you elaborate on the differences?
FYI:
I DID have “Various Artists” at first but after finding that the MP3Tag software only finds compilations that have “Various” instead of “Various Artists” as the "album artists, I switched to “Various” only.
I might be able to switch back though as all compilations have been correctly tagged recently.
Not sure what you mean by that. I am using mp3tag as well.
They’re small. Various Artists will have their album list automatically ordered by title, instead of release date.
Plexamp has a dedicated library category for compilations, where it lists all Various Artists albums.
It might also make some difference in how some of the automatic “Radios” work in Plexamp.
and there is also a small and elegant fix mentioned which I just implemented, so no reason to stick to “Various”, will change all back to “Various Artists”.
