Sjoerd writes:
Just for my information: why is chrony better than eg. ntp? I thought the
ntp daemon also adjusted the clock rate to synchronise the system with
the online ntp-servers.
Chrony corrects the clock more quickly when it is far off, does a better
job of keeping it correct when you are off-line, and corrects for hardware
clock drift when restarting after the machine has been shut down. It is
also trivially easy to configure: for most people it will "just work". It
has no support for atomic clocks, GPS clocks, etc. and does not support
some of the more esoteric features of the NTP protocol. Since it does not
use exactly the same algorithms that Dr. Mills has analyzed it is possible
(though unlikely) that a group of Chrony servers might be unstable under
some circumstances (ones you will never experience). Ntpd supports
numerous external clocks and can thus act as a stratum one server. It is
the reference implementation of the protocol and so by definition supports
all the features thereof. It's what national standards organizations such
as NIST use.