[CentOS-virt] Time

Van van-1 at yandex.ru
Sun Feb 17 13:26:29 UTC 2013



12.02.2013, 20:50, "Mauricio Tavares" <raubvogel at gmail.com>:
> On Thu, Jan 3, 2013 at 9:01 PM, Nico Kadel-Garcia <nkadel at gmail.com> wrote:
>
>>  On Jan 2, 2013, at 19:27, "James B. Byrne" <byrnejb at harte-lyne.ca> wrote:
>>>  I do that as well.  However, I run one on each host just to serve its
>>>  own guests and configure the host to run off our central ntp server.
>>  Unfortunately, before our upstream vendor's OS release 6, ntp.conf
>>  listed several loopback addresses by default. These allowed a confused
>>  ntpd to basically marry its siblings and eventually crossbreed itself
>>  to a fairly stange state. But it will report ntpd as active, which is
>>  why the Nagios check "chek_ntp_)time"  actually compares the time to a
>>  known good upstream NTP service.
>
>       Dumb question: why not use the vm host's clock instead? I am
> coming from libvirt but I would assume (bad idea I know) that if
> libvirt can see the host's clock in the client, so can kvm. If that is
> the case, something like
>
> hwclock -s -u
>
> should keep them in sync. I wrote a little cron job (see
> http://unixwars.blogspot.com/2013/01/restoring-time-on-sleeping-linux-vms.html)
> to compare the client time with the host. If the drift is large
> enough, sync them back. The reason for the cron job is so it works
> after client wakes up from a slumber. Just throwing an idea out there.
>
> On a side note, yes I did also write another script using ntpq and
> ntpdate to adjust time using ntp. I guess each solution has its
> merits. =)
>
>>>>>  4.  On each guest have a cron job that checks for ntpd at regular
>>>>>  intervals which reports failures and restarts the time service as
>>>>>  necessary. We use:
>>>>>   JOBNAME="Check ntpd status and restart if required" ; \
>>>>>     ntpstat > /dev/null && \
>>>>>     if [[ $? -gt 0 ]]; then /sbin/service ntpd start; fi
>>>>  Why not configure the ntpd daemon and stick with that?
>>>>  It does update on its own [1]. And ntpstat prints out the interval,
>>>>  which matches the one mentioned at [1].
>>>>  I don't believe the ntpstat script/job is necessary (I've never had to
>>>>  do more than set ntpd to run after configuring the servers it should
>>>>  poll).
>>  See above. The 'check_ntp_time' tool is much more flexible and complete.
>>  itten does work. It's part of the "nagios-plugions-ntp" package,
>>  available from EPEL and RPMforge.
>>  _______________________________________________
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>
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Hi. To get the same at all WM. I installed and configured ntp-server.
-- 
Трудно жить ничего не делая, но мы привыкли бороться с трудностями.


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