Plex (Docker) from LinuxServer.IO - mammothly slow scan speed, where are thumbnails saving?

  • Finally figured out how to manually map an SMB path. (Need to fix it on reboot, but anyhow...)


    Scanning 69 TV shows, maybe 2900 episodes.


    Kodi for Windows and LibreElec, can scan these in, maybe 30 to 60 minutes at most?

    Plex for Windows, around the same time.


    Plex (Docker) 'under' LibreElec took nearly 24 hours, not completed,....

    Many shows were identified (Show thumbnail, Show name, Season count, episode count) but actual EPISODE definitions, not pulled in, like episode title name, 'actual' episode thumbnail.


    Where are these thumbnails saving, is there a space limit? Is it a disk IO issue?

    Has anyone else seen this?


    I'm running LibreElec from USB key (god, this is very well designed, I'm very impressed)

    I just need to nail a few small issues and I can switch to this indefinitely.


    Long story short:

    Has anyone else had 'anomalies' scanning into the Plex server (docker) in the background, under LibreElec?

    Does anyone else run from USB key reliably, with a huge library for Plex? (because generally, performance on USB key has been astoundingly surprisingly good for Kodi)

    Edited once, last by FeFiFoFum ().

  • The library and the settings are all under the /config folder. So it depends on what folder you set it to in addon settings. By default it is under the addon_data folder on your main storage (usb drive).

  • Thank you for the response!


    For testing, I'm sticking with USB, but a few questions:


    Are there known issues with USB? can it be used for quite large libraries?


    Have you ever seen very very slow scanning for Plex on a USB key? (4c, 8t i5) brand new Bean Canyon NUC?


    Note that even when it finished, unfortunately Plex managed to miss many thumbnails (See: ykrrlri.png )

    It also missed episode title/synopsis / general detail information for example: (See: 3pdffz0.png )

    Yet some episodes scanned in fine: (See: oyu07p4.png )

    (This Scan for 2900 episodes, 69 shows took in excess of 12 hours)


    I'm really, really liking LibreElec so far, this feels very well designed and written, stable, fast - but the Plex (server) addon is giving me a hard time and I gotta admit, I do like to stream from time to time when away from home (Hence the need for Plex)


    Anyone else also welcome to reply.

  • It could be a number of things. Your media may not be named in the style Plex likes it so it may be having issues identifying. Or you may have been having internet connectivity issues and requests may have been timing out, or you may have been getting throttled by the metadata provider.


    The one thing I can think of with regards to usb drives is that flash drives usually have pretty awful write speeds. Plus, plex libraries can grow to hundreds of thousands of files easily and to hundreds of gigabytes (especially if you turn on video preview thumbnails). I really wouldn't recommend hosting the Plex library on a flash drive.


    With that said, there are no issues with the Plex docker container. Many people use with very large libraries (on ssds mostly) and scans are fairly quick.

  • It could be a number of things. Your media may not be named in the style Plex likes it so it may be having issues identifying. Or you may have been having internet connectivity issues and requests may have been timing out, or you may have been getting throttled by the metadata provider.


    The one thing I can think of with regards to usb drives is that flash drives usually have pretty awful write speeds. Plus, plex libraries can grow to hundreds of thousands of files easily and to hundreds of gigabytes (especially if you turn on video preview thumbnails). I really wouldn't recommend hosting the Plex library on a flash drive.


    With that said, there are no issues with the Plex docker container. Many people use with very large libraries (on ssds mostly) and scans are fairly quick.


    I can definitely confirm the media filenames are in perfect condition, scanning fine via LibreElec / Kodi on the same network..... at a much higher speed.


    I totally agree about the USB write speeds ,but I'd just expect it to either fail or spit out an error (or take even longer....) rather than just do the job poorly (not identifying all content)

    Also, Kodi scanned the data perfectly and quickly, (honestly I was surprised)

    Does LibreElec somehow make some kind of large container file for the thumbnails and then write into it? Reducing some disk load?

    Regardless, it's impressively reliable and fast, for a USB key.


    I will I guess, have no choice but to switch drive for testing I guess.

  • Well I've got my answer, I switched even to a regular, SATA 2.5" HDD in the NUC and it's working fine. Scanned the entire Plex library in under an hour AND Kodi at the same time (I did a fresh install)


    I really hope this thread helps others.



    Only thing that's a bit annoying / sad, is that LibreElec (Kodi) really did work wonderfully, even off USB, which surprises me - very handy feature. None the less, long term I do need Plex Server so I'm fine using an Internal disk.