I believe this to be an issue with the Official Plex image. It seems to happen when Plex is reading the media.

I have now installed the lscr.io/linuxserver/plex version as a test to see if this issue persists.

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Still seems to happen upon Plex playback and stopping, but the container swap didn't work.

I just swapped out my lscr.io/linuxserver/sabnzbd to binhex/arch-sabnzbd to see if the issue persists.

Edited June 18, 20251 yr by SkilledAlpaca

This is almost certainly and issue with Plex when it attempts to read any media on the server. I'm going to blow out the appdata/plex folder and start a fresh instance. I wonder if there are some issues with old configurations I tried and didn't clean up properly. Either way, I will be recreating the persistent data folder for now and trying again.

Unknown what the issue is at this point. I have rebuilt every single docker container on my Unraid server. Fresh appdata folders for each app, different container versions, and ran only three 'core' containers.

This can't be an issue with Docker and something is either fundamentally wrong with my setup or I have some kind of corrupt data that is killing the shfs service. Notably the crashes happen when Plex is about to start play back on media or right as the media playback is ending, but I've used two different Plex containers and the issue is still present.

Unraid has been amazing until recently and I'm not sure what else I can do beside attempting to delete literally everything and hope it doesn't happen again. I would really like not to lose multiple years worth of data trying to solve this issue if anyone has any other ideas. The last thing I could try would be disabling the Docker service fully and waiting but then the server gets zero use as it's primary use is media playback.

I will probably just going to swap to another product if this can't be solved or figured out because manually rebooting the server every 12 hours to 3 days is not a solution.

Edit: This has been an issue for OVER FIVE YEARS now with no solution.

https://forums.unraid.net/bug-reports/stable-releases/683-shfs-error-results-in-lost-mntuser-r939/page/8/?tab=comments

Edited June 30, 20251 yr by SkilledAlpaca

Jinxing it by posting, but I replaced the USB Flash Drive UnraidOS was on and I am holding steady at 9+ days of uptime with heavy and normal use.

I was originally using a SanDisk Cruzer Fit 16GB (SDCZ33) micro USB.

I swapped to a SanDisk Cruzer 128GB USB 2.0 Flash Drive (SDCZ36) I had lying around.

A cloud restore to this drive failed. The cloud download was nice as I was able to perform a fresh install of the latest UnraidOS. I then manually moved over a few items for Docker and plugins and it appears to be working without issue. I will mark this thread as solved if the uptime can hold for longer than 14 days with normal use.

Edit: Since replacing the USB flash drive, I have resumed all services, added additional containers and not a single crash in 23 days.

Edited August 8, 2025Aug 8 by SkilledAlpaca

Still working just fine? Dealing with this issue now.

@SkilledAlpaca - I'd love to know whether you feel like your rid of the issue now since the USB flash replacement?

On 8/11/2025 at 7:45 PM, the.phd said:

Still working just fine? Dealing with this issue now.

1 minute ago, thestraycat said:

@SkilledAlpaca - I'd love to know whether you feel like your rid of the issue now since the USB flash replacement?

As far as I can tell, swapping UBS's has resolved the issue. I will report back if I observe the error again.

@SkilledAlpaca Thanks for the update. Was there a reason you swapped it out? Was it showing as failing? Bad SMART status etc? Just wondering how i can tell whether i'm suffering from the same related issue. Mine has been in use for around 8 years now lol.

Edited August 13, 2025Aug 13 by thestraycat