NetworkManager disabled but still takes over systemd-networkd

czezz · 05-20-2019, 05:23 PM

In ubuntu 18.04 network is managed by netplan.
By default rendered in netplan is systemd-networkd - and this is what I want to use.
However, somehow NetworkManager is always active(running) no matter how much I disable it in systemd.

Code:

ubuntu@ubuntu:~$ sudo systemctl status network-manager.service
● NetworkManager.service - Network Manager
   Loaded: loaded (/lib/systemd/system/NetworkManager.service; disabled; vendor preset: enabled)
   Active: active (running) since Mon 2019-05-20 08:04:53 UTC; 10min ago
     Docs: man:NetworkManager(8)
 Main PID: 1125 (NetworkManager)
    Tasks: 3 (limit: 1056)
   CGroup: /system.slice/NetworkManager.service
           └─1125 /usr/sbin/NetworkManager --no-daemon

May 20 08:05:54 ubuntu NetworkManager[1125]: <warn>  [1558339554.2635] device (wlan0): re-acquiring supplicant interface (#3).
May 20 08:05:54 ubuntu NetworkManager[1125]: <error> [1558339554.4126] sup-iface[0xaaab181c8d00,wlan0]: error adding interface: wpa_supplicant couldn't grab this interface.
May 20 08:05:54 ubuntu NetworkManager[1125]: <info>  [1558339554.4127] device (wlan0): supplicant interface state: starting -> down
May 20 08:06:04 ubuntu NetworkManager[1125]: <warn>  [1558339564.2690] device (wlan0): re-acquiring supplicant interface (#4).
May 20 08:06:04 ubuntu NetworkManager[1125]: <error> [1558339564.3897] sup-iface[0xaaab181c8db0,wlan0]: error adding interface: wpa_supplicant couldn't grab this interface.
May 20 08:06:04 ubuntu NetworkManager[1125]: <info>  [1558339564.3907] device (wlan0): supplicant interface state: starting -> down
May 20 08:06:14 ubuntu NetworkManager[1125]: <warn>  [1558339574.2691] device (wlan0): re-acquiring supplicant interface (#5).
May 20 08:06:14 ubuntu NetworkManager[1125]: <error> [1558339574.3852] sup-iface[0xaaab181c8db0,wlan0]: error adding interface: wpa_supplicant couldn't grab this interface.
May 20 08:06:14 ubuntu NetworkManager[1125]: <info>  [1558339574.3854] device (wlan0): supplicant interface state: starting -> down
May 20 08:06:14 ubuntu NetworkManager[1125]: <info>  [1558339574.3855] device (wlan0): supplicant interface keeps failing, giving up

How strange!
If I stop network-manager, then whole network stops to work and by executing netplan apply it comes back finally without network-manager.

Question:
How to efficiently disable network-manager and let systemd-networkd take over?

evo2 · 05-20-2019, 09:32 PM

Hi,

what did you do to stop and disable it?

I guess you only stopped it. Eg

Code:

sudo systemctl stop NetworkManager.service

Unless you actually disable it, it will start at next boot.
To disable it:

Code:

sudo systemctl disable NetworkManager.service

This is the standard way of stopping and disabling services in systemd.

Evo2.

czezz · 05-21-2019, 01:12 AM

Hi Evo2,
thank you for reply.
I thought it is clearly shown and described in my initial post that NetworkManager is stopped and disabled. However, for some reason, after each reboot it starts.
I paste here specific line from systemctl (that I have underlined in red in the previous post) showing the disabled state.

Code:

Loaded: loaded (/lib/systemd/system/NetworkManager.service; disabled; vendor preset: enabled)

Just to make it crystal clear: yes, I have stopped and disabled NetworkManager. However, after reboot it starts automatically.

Could it be anything to do with this part: vendor preset: enabled ?
If so, how to change that part???

evo2 · 05-21-2019, 01:24 AM

Hi,

sorry missed that. I guess something other service is triggering it to start. Did you try looking at the full log to see it starting up after you stop it? Eg.

Code:

sudo journalctl -u NetworkManager

That may give you a clue as to what is going on.

Evo2.