Isn’t there normally a Docker pre-requisite check that warns you about missing kernel CONFIG_ options? Did this flag anything up?
From the aforementioned docs…
Am I using cgroup v2?
Yes if
/sys/fs/cgroup/cgroup.controllersis present.
And it’s present, so that may be as far as Docker checks. Indeed, docker info shows:
Server:
...
Cgroup Driver: systemd
Cgroup Version: 2