I earlier this week needed to restart a server with docker on it. The service controlling docker (amp) would not start anything because it was thinking the containers already existed. I found them under docker ps -a as "Removal in progress".
Much googling later I found a nice stacked command to remove them. Nope, ZFS kept complaining dataset does not exist. I tried to create them, then found some had dependent clones. It was a resolvable rabbit hole. Eventually I just renamed the containers and vowed this ZFS on Ubuntu on a whim was just a bad idea. I'll rebuild that server soon with a more traditional FS.
Also, I hate when a simple restart (read task) turns into a big hours long task.