If I install a new service then decide I don’t want that application anymore and delete it, the service is still listed in the output from
systemctl as error.
Where is this coming from and how can I remove them thoroughly?
My recipe for service obliteration (be careful with the
systemctl stop [servicename] systemctl disable [servicename] rm /etc/systemd/system/[servicename] rm /etc/systemd/system/[servicename] symlinks that might be related systemctl daemon-reload systemctl reset-failed
It is possible that the systemd service 'wraps' the old style scripts in /etc/init.d, so you may want to clean that up too, but that is not where systemd services live.
Sounds like you uninstalled it, but didn't remove the systemd hook:
# systemctl disable [servicename]
You are probably looking for
$ sudo systemctl reset-failed $
From the systemd man page:
Reset the "failed" state of the specified units, or if no unit name is passed, reset the state of all units. When a unit fails in some way (i.e. process exiting with non-zero error code, terminating abnormally or timing out), it will automatically enter the "failed" state and its exit code and status is recorded for introspection by the administrator until the service is restarted or reset with this command.
To re-iterate the list of commands:
systemctl stop [servicename]
chkconfig [servicename] off
Note: The 1st command is optional depending on whether you want keep the service running in the present session or not (as for this question the command should be used).
The 2nd command takes care of both disabling and removing (following the symlinks) the service.
Removing a service from systemd :
Systemd uses unit (file to define services) to remove a service the unit have to be removed... here is a list of unit locations :
/etc/systemd/system/ (and sub directories) ~/.config/systemd/user/ (and sub directories) /usr/lib/systemd/ (and sub directories) /etc/init.d/ (Converted old service system)
Refresh systemd :
systemctl daemon-reload systemctl reset-failed
Ghost services (not-found) :
Systemd can list ghost (not-found) services even if the unit is deleted for many reasons
(*) if a service is mentioned in other unit but does not exist systemd will still list that service with the state not-found even if there is not unit file... you can search what unit is using that service with a text search and edit those units (not recommended if you plan to install that service later)