I spent some time yesterday trying to understand why one of the machines here seemed to always take 90s
before shutting down or rebooting.
This article is a summary of the wild goose chase I embarked on to try and understand what was
happening.
When systemd
machines hang during shutdown, it usually means that there's a service that is not stopping fast enough
or it could be that systemd
is waiting for the DefaultTimeoutStopSec
timeout before
killing the remaining processes after all services have been stopped.
In my case, what I was seeing is the following:
[ OK ] Finished Reboot.
[ OK ] Reached target Reboot.
[ 243.652848 ] systemd-shutdown[1]: Waiting for process: containerd-shim, containerd-shim, containerd-shim, fluent-bit
These processes are part or k3s
, they are the parent processes of containers or processes running
in the containers themselves. Clearly, it has something to do with k3s
.
Update: the systemd bugfix was backported to Ubuntu 20.04.