2

Example [from Ubuntu 17.04]

The service is known as network-manager by systemd.

$ systemctl list-unit-files | grep network
network-manager.service                    enabled  

Looking for log information on that would give an impression that there are no entries.

$ sudo journalctl -u network-manager
-- No entries --
$ sudo journalctl -u network-manager.service
-- No entries --

Eventually I found out that it's:

$ sudo journalctl -u NetworkManager

Is there a consistent way to know under what name does a service goes in journald logs?

1

The confusion arises from having both NetworkManager and network-manager services on the system:

$ systemctl list-unit-files | grep NetworkManager
NetworkManager-dispatcher.service          enabled  
NetworkManager-wait-online.service         enabled  
NetworkManager.service                     enabled  
$ systemctl list-unit-files | grep network-manager
network-manager.service                    enabled 

and journalctl -u responding the same way for units without log entries and non existing units:

$ sudo journalctl -u network-manager
-- No entries --
$ sudo journalctl -u there-sure-isnt-a-service-named-like-this
-- No entries --

There is a simpler way of geting the log files beloning to a certain service and that is by using systemctl status.

$ sudo systemctl status network-manager.service 
● NetworkManager.service - Network Manager
   Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2017-08-15 16:12:15 CEST; 2 days ago
     Docs: man:NetworkManager(8)
 Main PID: 12950 (NetworkManager)
    Tasks: 4 (limit: 4915)
   CGroup: /system.slice/NetworkManager.service
           ├─12950 /usr/sbin/NetworkManager --no-daemon
           └─13011 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /var/run/dhclient-wlp4s0.pid -lf /var/lib/NetworkManager/dhclient-c19d95a3-6082-4c89-ab

Aug 17 15:09:48 alan-N551JM NetworkManager[12950]: <info>  [1502975388.9172] device (wlp4s0): supplicant interface state: associating -> 4-way handshake
Aug 17 15:09:48 alan-N551JM NetworkManager[12950]: <info>  [1502975388.9386] device (wlp4s0): supplicant interface state: 4-way handshake -> completed
Aug 17 15:11:48 alan-N551JM NetworkManager[12950]: <info>  [1502975508.7640] device (wlp4s0): supplicant interface state: completed -> authenticating
Aug 17 15:11:48 alan-N551JM NetworkManager[12950]: <info>  [1502975508.7707] device (wlp4s0): supplicant interface state: authenticating -> associating
Aug 17 15:11:48 alan-N551JM NetworkManager[12950]: <info>  [1502975508.7876] device (wlp4s0): supplicant interface state: associating -> 4-way handshake
Aug 17 15:11:48 alan-N551JM NetworkManager[12950]: <info>  [1502975508.8064] device (wlp4s0): supplicant interface state: 4-way handshake -> completed

which gives you the auto complete option for service names and errors for non existing services:

$ sudo systemctl status there-sure-isnt-a-service-named-like-this
Unit there-sure-isnt-a-service-named-like-this.service could not be found.

Note: I'm sure there is a connection between NetworkManager and network-manager, however it isn't important for the answer.

0

The exact names from the services can be found in:

/etc/systemd/system/*
/usr/lib/systemd/system/*

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.