Document that timedatectl set-ntp == systemctl {enable/disable} systemd-timesyncd.service · Issue #798 · systemd/systemd
I'm confused by the documentation, on whether timedatectl set-ntp ONLY enables or disables systemd-timesyncd.service, or if it does this AND other things. Are they interchangeable? I'm betting they aren't interchangeable, because the other systemd services don't have a non-systemctl way to be enabled/disabled (as far as I've ran into.)
Asking, because "timedatectl set-ntp true" fails from the boot cd in arch-chroot with "Failed to create bus connection: No such file or directory". But, systemctl runs without needing a bus connection.
systemctl runs without a bus connection because it has fallback logic to enable/disable units in the absence of a usable bus connection. timedatectl defers work to timedated by communicating with it over the bus. So, it makes sense that systemctl works and timedatectl fails in the absence of a system bus. This situation ought to improve once kdbus is around.
Looking at the code, calling timedatectl set-ntp true is equivalent to calling systemctl --now enable systemd-timedated. Similarly, timedatectl set-ntp false is equivalent to calling systemctl --now disable systemd-timedated.
It only controls systemd-timesyncd.service.
Today the setting is pretty redundant since "systemctl enable systemd-timesyncd.service" is also hooked up to PolicyKit, and thus clients such as GNOME could just invoke that directly.
We should probably update the man page to explain in more detail what this does.
poettering
changed the title
Clarification on if timedatectl set-ntp == systemctl {enable/disable} systemd-timesyncd.service
Document that timedatectl set-ntp == systemctl {enable/disable} systemd-timesyncd.service
We should still document this. Reopening hence.
poettering added a commit to poettering/systemd that referenced this issue
Aug 16, 2015
This extends on the relationship between timedatectl's set-ntp command and its effect on the systemd-timesyncd.service unit. This also links that unit back to the timedatectl man page. Closes systemd#798.