Docker containers failing to update / disappearing [solved -- slow performance issue]

[Transient]

I was able to resolve this issue, but wanted to share in case it helps someone else.

 

Today I noticed many of my Docker containers weren't updating. They'd run through the update process without error, but in the end would still be running the outdated version.

 

Upon a closer inspection of the update window, I noticed the pull did not complete extracting. I believe Unraid aborts the pull after a set amount of time, but then proceeds with a stop / remove / start of the container anyway, thereby finishing with the same version you already had previously.

 

In my case, there were two reasons this timeout was occurring:

1. docker.img was stored on the array
2. the array was undergoing a parity check

 

After moving it off the array, the problem was solved.

 

In addition to this, I've had the rare instance where a container disappears. I could never figure out why this occurred and assumed it was due to a failed update, but I wouldn't notice until some time later.

 

Today I finally saw the problem occur and it's related to the same issue above. The container would fail to stop due to the stop timeout being hit (which is configurable), but the the update process continues anyway. Next it would fail to remove the container and then fail to create a new container because one with the same name already exists. Then a few moments later, the remove command is processed and the container is gone!

 

Both of these problems can be resolved by simply not putting docker.img on the array. Or possibly configuring things such that you never update your containers during a parity operation.

Edited February 4 by Transient