I run my Plex server on an Intel Nuc 11 and I recently switched from Windows 11 to Ubuntu 24.04. I installed the snap version of Plex server.
Now the plex media scan process runs every night.
In settings → server I have these settings:
Scan my library automatically: off
Run a partial scan when changes are detected : off
Include music libraries in automatic updates: off
Scan my library periodically: off
Generate video preview thumbnails: never
Generate intro video markers: never
Generate credits video markers: never
Generate chapter thumbnails: never
Analyze audio tracks for loudness: never
Analyze audio tracks for sonic features: never
In manage library → edit → advanced I have these:
Enable video preview thumbnails: off
Enable credits detection: off
But the plex media scan process still runs every night. It starts at 02:00 am. I don’t know how long it scans, I go to bed beween 02:00 and 03:00. When I wake up it’s finished. In the server itself there is no scanning activity and the process is not listed in the system monitor gui. I can only see it when I do a top in the terminal.
Although it doesn’t use much cpu the temperature rise is disproportionate and the NUC gets a lot louder. The main problem is that I can’t go into suspension mode anymore, this process prevents it. When I stop the server with “sudo snap stop plexmediaserver” everything is back to normal. The NUC is cool, quiet and I can suspend it.
What exactly gets scanned every night and how can I prevent it?
Settings - Server - Scheduled Tasks
Update all libraries during maintenance
You might want to adapt the the period for the maintenance to your usage pattern. Move it to a time where you aren’t sleeping beside the machine, but aren’t usually also not using the server to watch something.
Thank you very much for the super quick reply.
This setting was off but the scheduled tasks have to be the solution. I haven’t even looked into them, I feel quite dumb now
I will play around with them and update this post tomorrow.
A snap installation of Plex Media Server cannot use hardware accelerated transcoding & tone mapping, as snaps are isolated from the hardware and operating system.
It is possible to transfer a snap installation to a native Linux installation if desired.
Otherwise, you can uninstall the snap version, download the .deb file from plex.tv, and install with “dpkg -i …” (Plex Docs → Installation).
The Plex Linux Tips document is also worth a read. It can help you avoid common pitfalls with installing Plex Media Server on Linux systems.
@FordGuy61
Thank you for the explainations and links, I already bookmarked them.
I just tried transcoding a 4k HDR file to 1080p 8Mbps and as you said HW acceleration didn’t work. At least I think it didn’t, my CPU was at 90+% but the quality was great.
To be honest, I’m new to 4k as well (new TV). I need to read up on all that transcoding and tonemapping stuff. For now I’m glad everything works and as a Linux beginner I thought it would be easier to go for the snap. I guess I try out the .deb installation when the bug is fixed.
An example would be using an older GPU that does not support HEVC video. The decode would happen in software and the encode would happen using the GPU.
It could also happen if you exceed the limitations of the GPU. For example, Nvidia limits their consumer (GTX) cards to a maximum of 8 simultaneous encodes. The number of decodes is not limited. Were you to have 8 concurrent transcodes, the ninth would be decoded in hardware and encoded in software.
The Nvidia example assumes the card has enough memory to handle all those transcodes. If it does not, Plex will switch to transcoding with the CPU.
I do not know the inner workings of the Plex transcoder. AFAIK, the slower process waits, if necessary. I’ve never heard of it occurring or being a problem.
The main thing is for the full transcode to occur in real time (24 fps, 50 fps, etc.) or faster. If it does not, then the end user will experience buffering.
