[systemd-devel] Unload disabled units

[Michael Chapman]

On Sun, 15 Sep 2019, Daniel Duong wrote:
> Hi,
> 
> I have a 2 template units: 1 for a service and 1 for a socket. Each
> instance is a version of my web application.
> 
> After a successful deploy, I stop and disable the old version and I
> enable the new one:
> 	systemctl start belleshop at 0.2.socket
> 	# Test that everything is fine
> 	systemctl enable belleshop at 0.2.socket
> 	systemctl stop belleshop at 0.1.socket
> 	systemctl stop belleshop at 0.1.service
> 	systemctl disable belleshop at 0.1.socket
> 
> I've done that for a few versions now, and it seemed to work OK. There
> is a little problem though. The old versions are still loaded:
> 
> 	$ systemctl --no-legend --all list-units belleshop@*
> 	belleshop at 0.110.service loaded active   running Belleshop server
> 	belleshop at 0.34.service  loaded inactive dead    Belleshop server
> 	belleshop at 0.36.service  loaded inactive dead    Belleshop server
> 	belleshop at 0.37.service  loaded inactive dead    Belleshop server
> 	[...]
> 	belleshop at 0.110.socket  loaded active   running Belleshop socket
> 	belleshop at 0.34.socket   loaded inactive dead    Belleshop socket
> 	belleshop at 0.36.socket   loaded inactive dead    Belleshop socket
> 	belleshop at 0.37.socket   loaded inactive dead    Belleshop socket
> 	[...]
> 
> Is there any way I can unload these old versions?

You should check to see if anything is actually still referencing these 
units. Try `systemd-analyze dump` and see if any "ReferencedBy" entries 
appear for these units.