systemd always load old service setting

Question

I have a strange question on Ubuntu Server 20.04, which is upgraded from 19.10.

I have a service defined while 19.10 in systemd/system. It works without any problem in that version.

Now, I need to change some setting in the service file. So I edit the file, use daemon-reload to reload it and try to use the new one, but systemd keep to use the old one. I know it is using the old one because the 2 versions point to different binary which I can see from status displaying.

Every time I start the service, systemctl warns me to use daemon-reload to reload the changed file. Use daemon-reload, even reboot won't fix.

I tried to remove the service file and reload it. It says service is not found while trying starting, which is good. But when I put the changed file back, it still use the old one while nothing is wrong with the service file.

I wonder maybe there is another place than /etc/systemd/system to save all settings?

Thanks.

Answer 1

Problem resolved.

The problem found it at the [unit] of the service file, one line says: SourcePath=/etc/init.d/<old.service.file>

After remove that line and reload, the problem is fixed.

It's still strange that the service file and the requested one in init.d are cached some where in systemd.

I leave this question here for who encounter the same problem in the future.