NTP problem for virtual RHEL 4 server on VmWare

Kenneth Holter kenneho.ndu at gmail.com
Mon Nov 10 06:59:28 EST 2008


Thank you for the link.

I'll see if the kernel parmameters solves the problem. I'll try this
solution before shutting off NTP on the client, as this complies better with
out monitoring setup.

I noticed in the document that "..In all cases use NTP instead of Vmware
tools periodic time synchronization". Is this periodic time sync what
happens if I set "tools.syncTime = TRUE"?

I was asked for details of the Vmware host, so here they are:

   - PowerEdge R900
   - ESX server 3.5.0

Regards,
Kenneth


On 11/10/08, Andre Dill <Andre.Dill at datacash.co.za> wrote:

> Hi,
>
> I had the same problem with my RHEL 4 and 5 servers. I found the KB article
> from VMWare to be very helpful.
>
> http://kb.vmware.com/kb/1006427
>
> Regards,
>
> --
> Andre Dill
> Senior Systems Administrator
> DataCash
>
> Tel (Direct): +27 (0)21 528 4618
>
> DataCash (PTY) Ltd, No1 Waterview Park, Century City Boulevard,
> Century City. 7446. Cape Town, South Africa.
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> www.datacash.com
>
>
> > -----Original Message-----
> > From: redhat-list-bounces at redhat.com [mailto:redhat-list-
> > bounces at redhat.com] On Behalf Of Kenneth Holter
> > Sent: 07 November 2008 11:49 AM
> > To: redhat-list at redhat.com
> > Subject: NTP problem for virtual RHEL 4 server on VmWare
> >
> > Hei.
> >
> >
> > One of our RHEL 4 servers running on VmWare has a quite serious NTP
> > problem.
> > I know that NTP can be an issue when running red hat boxes on VmWare,
> > so as
> > a fix I put this small script in a file in /etc/cron.hourly:
> >
> >
> > [root at server cron.hourly]# cat ntpdate
> > #!/bin/sh
> > /etc/init.d/ntpd stop
> > ntpdate 1.2.3.4 >> /tmp/time_adjust.log
> > /etc/init.d/ntp
> >
> >
> > After investigating the "/tmp/time_adjust.log" file, I was quite
> > surprised
> > by the amount of drift found on one particular server. Consider this
> > extract
> > from the file:
> >
> > 6 Nov 20:00:01 ntpdate[19373]: step time server 1.2.3.4 offset -
> > 60.504153
> > sec
> >  6 Nov 20:00:52 ntpdate[19666]: step time server 1.2.3.4 offset -
> > 8.735440
> > sec
> >  6 Nov 20:01:00 ntpdate[19689]: step time server 1.2.3.4 offset -
> > 1.635632
> > sec
> >  6 Nov 20:54:06 ntpdate[24198]: step time server 1.2.3.4 offset -
> > 415.894712
> > sec
> >  6 Nov 21:01:01 ntpdate[24920]: adjust time server 1.2.3.4 offset
> > 0.136833
> > sec
> >  6 Nov 22:01:02 ntpdate[29943]: adjust time server 1.2.3.4 offset -
> > 0.114253
> > sec
> >  6 Nov 23:01:01 ntpdate[2519]: adjust time server 1.2.3.4 offset -
> > 0.036345
> > sec
> >  7 Nov 00:01:00 ntpdate[7577]: step time server 1.2.3.4 offset -
> > 1.064935 sec
> >  7 Nov 01:00:57 ntpdate[12697]: step time server 1.2.3.4 offset -
> > 3.922577
> > sec
> >  7 Nov 02:00:21 ntpdate[17733]: step time server 1.2.3.4 offset -
> > 40.421825
> > sec
> >  7 Nov 02:01:00 ntpdate[17777]: step time server 1.2.3.4 offset -
> > 1.123175
> > sec
> >  7 Nov 02:57:23 ntpdate[22542]: step time server 1.2.3.4 offset -
> > 218.649820
> > sec
> >  7 Nov 03:00:36 ntpdate[22900]: step time server 1.2.3.4 offset -
> > 25.284528
> > sec
> >  7 Nov 03:00:58 ntpdate[22940]: step time server 1.2.3.4 offset -
> > 3.104130
> > sec
> >  7 Nov 03:52:32 ntpdate[27430]: step time server 1.2.3.4 offset -
> > 509.363952
> > sec
> >  7 Nov 03:59:50 ntpdate[27943]: step time server 1.2.3.4 offset -
> > 71.430354
> > sec
> >  7 Nov 04:00:52 ntpdate[28236]: step time server 1.2.3.4 offset -
> > 9.344907
> > sec
> >  7 Nov 04:01:00 ntpdate[28259]: step time server 1.2.3.4 offset -
> > 1.237651
> > sec
> >  7 Nov 05:01:01 ntpdate[1363]: adjust time server 1.2.3.4 offset
> > 0.390149
> > sec
> >  7 Nov 06:01:01 ntpdate[6419]: adjust time server 1.2.3.4 offset -
> > 0.185112
> > sec
> >  7 Nov 07:01:02 ntpdate[11493]: adjust time server 1.2.3.4 offset -
> > 0.228884
> > sec
> >  7 Nov 08:00:59 ntpdate[16579]: step time server 1.2.3.4 offset -
> > 2.166519
> > sec
> >  7 Nov 09:00:38 ntpdate[21522]: step time server 1.2.3.4 offset -
> > 23.169420
> > sec
> >  7 Nov 09:01:02 ntpdate[21558]: adjust time server 1.2.3.4 offset -
> > 0.492106
> > sec
> >  7 Nov 09:59:26 ntpdate[26329]: step time server 1.2.3.4 offset -
> > 95.154264
> > sec
> >  7 Nov 10:00:55 ntpdate[26639]: step time server 1.2.3.4 offset -
> > 5.997955
> > sec
> >  7 Nov 10:01:01 ntpdate[26658]: step time server 1.2.3.4 offset -
> > 0.506367
> > sec
> >
> >
> > Does anyone know what may be causing the RHEL box to drift as much as
> > 500
> > seconds in only one hour?
> >
> > Regards,
> > Kenneth Holter
> > --
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