Look into the "panic" option to ntpd - once the gap gets to big (such as
when the VM is suspended for a few hours) it goes into freewheel and
doesn't sync - its in the ntp docs.
ntpd doesn't work well (you get ages where a machine is way out of date,
or fails to sync ever. I run either chrony (same problem) or ntpd and
run a script on startup to restart guest ntp/chrony from the host via ssh.
I don't think serious users suspend vm's much or this would have been
fixed long ago.
BillK
On 23/09/15 23:44, Jérôme wrote:
Hi.
Thanks for answering.
Le 2015-09-23 17:34, Dominique Ramaekers a écrit :
> Linux has two methods to use ntp:
>
> ntpdate:
> It will run once at boot time to sync time. (This is probably
> installed on your system)
> It will not run after suspend and resume... => no correction
Nope. This is not installed on my system.
> ntpd:
> Continuously adjusts time. The deamon also calculates the drift to
> anticipate differences.
> I use this one and works perfectly.
This is installed (package ntp, Debian Jessie) and runs (I see
/usr/sbin/ntpd in `ps aux`). But after more than 24h, the 2'17 gap
between hwclock and date has not reduced a bit.
I guess this is not the place for me to debug my ntp issues, apart maybe
from what could be related to the virtualization itself.
I understood from my readings (can't remember where precisely) that the
fact that ntp wouldn't work was "normal", but if it is not, maybe trying
to have it working is the way to go, rather than searching for a way to
automatize guest-set-time.