

Chrony – A versatile implementation of the Network Time Protocol  - ingve
http://chrony.tuxfamily.org/index.html

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uuilly
I've been using chrony to sync 18 CPUs in a realtime application. I've found
it to be a mixed bag. Once it gets syncing, it's really good. I've got it set
up so I'm accurate to w/in a few microseconds on my LAN. But getting the
initial sync fast is extremely unintuitive, impossible, poorly documented or
some combo of all three. I don't think it was designed with the thought that
the machines would get rebooted every night -- which is our case. I had to
write some upstart scripts to perform the initial sync and then let chrony
take over from there...

~~~
mlichvar
chrony maintainer here. If the initial sync is slow, it probably means the
initial offset of the clock is large and chronyd is correcting it by slewing,
which may take a long time. You can use the initstepslew or makestep directive
to step the clock on start. A configuration optimized for a fast and tight
sync with a local NTP server could be:

    
    
      server ntp.lan minpoll 2 maxpoll 4 iburst
      makestep 0.1 1

~~~
uuilly
Thanks! I'll try it.

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2bluesc
I used to use this and then just switched to systemd's timesyncd. It's already
integrated and less dependencies.

[https://wiki.archlinux.org/index.php/Systemd-
timesyncd](https://wiki.archlinux.org/index.php/Systemd-timesyncd)

[http://www.freedesktop.org/software/systemd/man/systemd-
time...](http://www.freedesktop.org/software/systemd/man/systemd-
timesyncd.service.html)

~~~
digi_owl
Not sure i would consider being part of the whole systemd blob as having "less
dependencies".

Maybe if your chosen distro has adopted systemd already, but then the
dependencies are masked but that fact rather than reduced in a real sense.

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apenwarr
djb's clockspeed is amazingly simple, straightforward, and reliable:
[http://cr.yp.to/clockspeed.html](http://cr.yp.to/clockspeed.html) . I prefer
it to the more complicated ntp daemons because I can make it do exactly what I
want in weird situations.

