I wish to configure Time Synchronisation on Ubuntu 16.04.4 but timedatectl give Failed to create bus connection: No such file or directory

Question

When I look at https://help.ubuntu.com/lts/serverguide/NTP.html I can see the current time configuration with timedatectl but I always get an error.

$ timedatectl status
Failed to create bus connection: No such file or directory
$ sudo timedatectl status
Failed to create bus connection: No such file or directory

# timedatectl status
Failed to create bus connection: No such file or directory

There are no ntp packages installed and the service is running normal.

# systemctl status systemd-timesyncd
* systemd-timesyncd.service - Network Time Synchronization
   Loaded: loaded (/lib/systemd/system/systemd-timesyncd.service; enabled; vendor preset: enabled)
  Drop-In: /lib/systemd/system/systemd-timesyncd.service.d
           `-disable-with-time-daemon.conf
   Active: active (running) since Thu 2018-03-15 15:37:16 CET; 17h ago
     Docs: man:systemd-timesyncd.service(8)
 Main PID: 1801 (systemd-timesyn)
   Status: "Synchronized to time server 193.190.253.212:123 (1.be.pool.ntp.org)."
   CGroup: /system.slice/systemd-timesyncd.service
           `-1801 /lib/systemd/systemd-timesyncd

Mar 15 15:37:16 linux-repo systemd[1]: Starting Network Time Synchronization...
Mar 15 15:37:16 linux-repo systemd[1]: Started Network Time Synchronization.
Mar 15 15:37:21 linux-repo systemd-timesyncd[1801]: Synchronized to time server 193.190.253.212:123 (1.be.pool.ntp.org).
Mar 16 08:28:56 linux-repo systemd[1]: Started Network Time Synchronization.

Answer 1

I found the solution here: Thanks for the answer but I found the solution here: https://stackoverflow.com/questions/43907925/ubuntu-timedatectl-fails-in-docker-container

On a minimal Ubuntu 16.04 installation (like mine) the dbus package is not installed. So apt-get install dbus resolved the problem.

Answer 2

timedatectl trys to open serveral files/devies. One of them fails in your case. Start the timedatectl with strace and search for error messages:

$ strace -o /tmp/timedatectl.log timedatectl status
$ grep "^open(" /tmp/timedatectl.log
...
open("/etc/localtime", O_RDONLY|O_CLOEXEC) = 4
open("/dev/rtc", O_RDONLY|O_CLOEXEC)    = 4
open("/etc/localtime", O_RDONLY|O_CLOEXEC) = 4
...

If you know which file/device creates the problem you can start fixing it.