Recently I'm having a recurring issue where, a few times a week, I'm flooded with emails about my Docker image utilization exploding out of the blue:

I have a 100GB vdisk, so whatever's going on uses up over 60GB very quickly. Then once it reaches 100% it eventually resets back to 45% where it normally sits.

I suspect it's related to Plex, because I've been having odd issues with it the past couple months. It crashes and requires a docker restart almost every day, and last night during the appdata backup I got this new error:

I'm hoping someone here will recognize these symptoms and can shed some light on what's happening. Or at least give some pointers on how to go about troubleshooting this.

Sounds like 2 different problems.

For the usage, do you have some huge containers like AI stuff?`Or misconfigured the appdata backup plugin to store backups in the wrong place?

For the backup, are you correctly stopping the plex container and any other that might share amount during the backup?

Edited June 20, 20251 yr by Kilrah

No I'm not running any unusually large containers. No AI stuff. Just Plex, Immich, Arr stack, etc. Haven't added any new containers recently.

As for the backup, I've never had to manually mess with it one way or the other. The AppData backup plugin usually auto-stops each docker before backing up. Apparently this time it had trouble stopping the Plex container. I've been running the same stuff for years and never had any issues with it. I haven't changed any of the settings recently.

The next time I get notifications about my vdisk usage going crazy how can I go about determining which Docker is the culprit?

If you can catch it while it's happening it might be useful to hit the "container size" button on the Docker page and comparing with the same in steady state.

You're really in Docker Image mode and not folder, right?

11 minutes ago, Kilrah said:

If you can catch it while it's happening it might be useful to hit the "container size" button on the Docker page and comparing with the same in steady state.

I get Pushover notifications on my phone when it happens, so I should be able to catch it and try that. Thanks.

13 minutes ago, Kilrah said:

You're really in Docker Image mode and not folder, right?

Sorry, I don't know what you mean here. Docker Image mode vs folder mode? I guess whatever the default is.

Edited June 20, 20251 yr by Gazeley

1 minute ago, Gazeley said:

Sorry, I don't know what you mean here. Docker Image mode vs folder mode? I guess whatever the default is.

Default is Image and you said you had a 100GB image so that seems like what you're using, but IF you were in Folder mode then usage would reflect the usage of the storage location it's in so could be misleading. Check in Docker settings with array stopped.

Edited June 20, 20251 yr by Kilrah

For me, it's been plex doing scheduled maintenance on the database. For some reason I notice it during then and afterwords it's back to normal levels.

2 minutes ago, MowMdown said:

For me, it's been plex doing scheduled maintenance on the database

Funny you should mention that. When I made this thread I noticed Plex was backing up the database. I just went to check on it and noticed it crashed again. I don't see anything in the logs:

And the docker still shows as running...

...but it doesn't load when I try to open the WebUI or from the app. Restarting the docker fixes it but this is becoming increasingly annoying. Is there some way to easily backup my watch history, collections, posters, etc - burn the whole thing down - and then start fresh and import that data? I feel like my 12 year old Plex database has been corrupted or something and I just need to redo it. I tried running "Optimize database" recently and it crashed the docker, after running for hours.

Edited June 20, 20251 yr by Gazeley