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Old 12-12-2007, 04:50 AM
"Jason Pyeron"
 
Default ntpd

I am running a server inside of VMWare, and the clock gains ~30 seconds
every 1000 seconds or 1.03X.

I need to keep the drift under the magic 1000 limit that ntpd kills its
self, but despite setting maxpoll really low I get:

Dec 11 23:58:14 host ntpd[4909]: kernel time discipline status change 41
Dec 11 23:59:17 host ntpd[4909]: kernel time discipline status change 1
Dec 11 23:59:17 host ntpd[4909]: time correction of -1123 seconds exceeds
sanity limit (1000); set clock manually to the correct UTC time.


/etc/ntp.conf:

server time.intranet.pdinc.us maxpoll 7

Ideas? If I cannot get ntpd working, then I will have to resort to a cron *
* * * * rdate -s time.intranet.pdinc.us

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- -
- Jason Pyeron PD Inc. http://www.pdinc.us -
- Sr. Consultant 10 West 24th Street #100 -
- +1 (443) 269-1555 x333 Baltimore, Maryland 21218 -
- -
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Old 12-12-2007, 05:24 AM
"Jason Pyeron"
 
Default ntpd

>
> I am running a server inside of VMWare, and the clock gains
> ~30 seconds
> every 1000 seconds or 1.03X.

...

> Ideas? If I cannot get ntpd working, then I will have to
> resort to a cron *
> * * * * rdate -s time.intranet.pdinc.us
>


ntpdc -p

remote local st poll reach delay offset disp
================================================== =====================
=time 0.0.0.0 3 64 1 0.00046 -34.34546 7.93799
=LOCAL(0) 127.0.0.1 10 64 1 0.00000 0.000000 7.93752
=time2 0.0.0.0 3 64 1 0.00040 -34.33556 7.93799
=time3 0.0.0.0 3 64 1 0.00050 -34.33738 7.93799

ntpdc -c sysinfo

system peer: 0.0.0.0
system peer mode: unspec
leap indicator: 11
stratum: 16
precision: -16
root distance: 0.00000 s
root dispersion: 0.00099 s
reference ID: [0.0.0.0]
reference time: 00000000.00000000 Thu, Feb 7 2036 1:28:16.000
system flags: auth monitor ntp kernel stats
jitter: 0.000015 s
stability: 0.000 ppm
broadcastdelay: 0.007996 s
authdelay: 0.000000 s


But still no clock setting...


By the time I wrote the above:

st poll reach delay offset disp
=======================================
3 64 37 0.00058 -52.85483 0.43922
10 64 37 0.00000 0.000000 0.43831
3 64 37 0.00034 -52.79517 0.43925
3 64 37 0.00055 -52.80582 0.43925


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Old 12-12-2007, 08:49 AM
Tru Huynh
 
Default ntpd

On Wed, Dec 12, 2007 at 01:24:23AM -0500, Jason Pyeron wrote:
> >
> > I am running a server inside of VMWare, and the clock gains
> > ~30 seconds
> > every 1000 seconds or 1.03X.
>
> ...

What CentOS, kernel version?

Maybe a better followup to the centos-virt mailing list...

>
> > Ideas? If I cannot get ntpd working, then I will have to
> > resort to a cron *
> > * * * * rdate -s time.intranet.pdinc.us
> >
>
>
> ntpdc -p
>
> remote local st poll reach delay offset disp
> ================================================== =====================
> =time 0.0.0.0 3 64 1 0.00046 -34.34546 7.93799
> =LOCAL(0) 127.0.0.1 10 64 1 0.00000 0.000000 7.93752
> =time2 0.0.0.0 3 64 1 0.00040 -34.33556 7.93799
> =time3 0.0.0.0 3 64 1 0.00050 -34.33738 7.93799
>

why don't you configure ntpd to an external server?

> ntpdc -c sysinfo
>
> system peer: 0.0.0.0
> system peer mode: unspec
> leap indicator: 11
> stratum: 16
> precision: -16
> root distance: 0.00000 s
> root dispersion: 0.00099 s
> reference ID: [0.0.0.0]
> reference time: 00000000.00000000 Thu, Feb 7 2036 1:28:16.000
> system flags: auth monitor ntp kernel stats
> jitter: 0.000015 s
> stability: 0.000 ppm
> broadcastdelay: 0.007996 s
> authdelay: 0.000000 s
>
>
> But still no clock setting...
>
>
> By the time I wrote the above:
>
> st poll reach delay offset disp
> =======================================
> 3 64 37 0.00058 -52.85483 0.43922
> 10 64 37 0.00000 0.000000 0.43831
> 3 64 37 0.00034 -52.79517 0.43925
> 3 64 37 0.00055 -52.80582 0.43925
>
>
no issue here:
[tru@centos5-i386-vm ~]$ date
Wed Dec 12 10:46:02 CET 2007
[tru@centos5-i386-vm ~]$ sudo ntpdc -p
remote local st poll reach delay offset disp
================================================== =====================
=LOCAL(0) 127.0.0.1 10 64 1 0.00000 0.000000 2.81735
=ntp.pasteur.fr 157.99.90.56 1 64 1 0.00131 0.004765 2.81740
[tru@centos5-i386-vm ~]$ ntpdc -p
remote local st poll reach delay offset disp
================================================== =====================
=LOCAL(0) 127.0.0.1 10 64 1 0.00000 0.000000 2.81735
=ntp.pasteur.fr 157.99.90.56 1 64 1 0.00131 0.004765 2.81740
[tru@centos5-i386-vm ~]$ ntpdc -c sysinfo
system peer: 0.0.0.0
system peer mode: unspec
leap indicator: 11
stratum: 16
precision: -20
root distance: 0.00000 s
root dispersion: 0.00055 s
reference ID: [73.78.73.84]
reference time: 00000000.00000000 Thu, Feb 7 2036 7:28:16.000
system flags: auth monitor ntp kernel stats
jitter: 0.000000 s
stability: 0.000 ppm
broadcastdelay: 0.003998 s
authdelay: 0.000000 s
[tru@centos5-i386-vm ~]$ uname -a
Linux centos5-i386-vm.bis.pasteur.fr 2.6.18-53.1.4.el5vm #1 SMP Thu Dec 6 11:09:34 EST 2007 i686 athlon i386 GNU/Linux
[tru@centos5-i386-vm ~]$ ntpdc -p
remote local st poll reach delay offset disp
================================================== =====================
=LOCAL(0) 127.0.0.1 10 64 17 0.00000 0.000000 0.96858
*ntp.pasteur.fr 157.99.90.56 1 64 17 0.00131 0.004765 0.96953
[tru@centos5-i386-vm ~]$

Cheers,

Tru
--
Tru Huynh (mirrors, CentOS-3 i386/x86_64 Package Maintenance)
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xBEFA581B
_______________________________________________
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http://lists.centos.org/mailman/listinfo/centos
 
Old 12-12-2007, 09:31 AM
Luke Dudney
 
Default ntpd

On 12/12/2007 05:50, Jason Pyeron wrote:

I am running a server inside of VMWare, and the clock gains ~30 seconds
every 1000 seconds or 1.03X.

I need to keep the drift under the magic 1000 limit that ntpd kills its
self, but despite setting maxpoll really low I get:

Dec 11 23:58:14 host ntpd[4909]: kernel time discipline status change 41
Dec 11 23:59:17 host ntpd[4909]: kernel time discipline status change 1
Dec 11 23:59:17 host ntpd[4909]: time correction of -1123 seconds exceeds
sanity limit (1000); set clock manually to the correct UTC time.


/etc/ntp.conf:

server time.intranet.pdinc.us maxpoll 7

Ideas? If I cannot get ntpd working, then I will have to resort to a cron *
* * * * rdate -s time.intranet.pdinc.us




I would love to see some clear, accurate guidance from anyone regarding
time synchronisation within Linux VMs under VMware. From what I've been
able to gather, VMware recommend that you disable any in-guest external
synchronisation (ntp, windows time etc) and use vmware-tools to sync the
time. For now the approach seems to involve trying random kernel boot
options and a lot of reboots until you find something that works.


I'd be happy to have my understanding of this issue clarified!

cheers
Luke
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http://lists.centos.org/mailman/listinfo/centos
 
Old 12-12-2007, 12:07 PM
"Blackburn, Marvin"
 
Default ntpd

-----Original Message-----
From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf
Of Luke Dudney
Sent: Wednesday, December 12, 2007 5:32 AM
To: CentOS mailing list
Subject: Re: [CentOS] ntpd

On 12/12/2007 05:50, Jason Pyeron wrote:
> I am running a server inside of VMWare, and the clock gains ~30 seconds
> every 1000 seconds or 1.03X.
>
> I need to keep the drift under the magic 1000 limit that ntpd kills its
> self, but despite setting maxpoll really low I get:
>
> Dec 11 23:58:14 host ntpd[4909]: kernel time discipline status change 41
> Dec 11 23:59:17 host ntpd[4909]: kernel time discipline status change 1
> Dec 11 23:59:17 host ntpd[4909]: time correction of -1123 seconds exceeds
> sanity limit (1000); set clock manually to the correct UTC time.
>
>
> /etc/ntp.conf:
>
> server time.intranet.pdinc.us maxpoll 7
>
> Ideas? If I cannot get ntpd working, then I will have to resort to a cron
*
> * * * * rdate -s time.intranet.pdinc.us
>
>

I would love to see some clear, accurate guidance from anyone regarding
time synchronisation within Linux VMs under VMware. From what I've been
able to gather, VMware recommend that you disable any in-guest external
synchronisation (ntp, windows time etc) and use vmware-tools to sync the
time. For now the approach seems to involve trying random kernel boot
options and a lot of reboots until you find something that works.

I'd be happy to have my understanding of this issue clarified!

cheers
Luke



Luke,
We have had similar problems with vm's running fast. I was under the same
impression that you were about
the recommended method to sync time. But after working the issue with
vmware for several months, they backed
down on their recommendation and stated that they did not recommend using
both methods togethter: syncing with host AND ntpd.
They said either would be fine, not both. This didnt entirely fix my
problem -- still runs a second or two fast, but much better than before.
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 12-12-2007, 12:14 PM
"Akemi Yagi"
 
Default ntpd

On Dec 12, 2007 5:07 AM, Blackburn, Marvin <mblackburn@glenraven.com> wrote:
>
> -----Original Message-----
> From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf
> Of Luke Dudney
> Sent: Wednesday, December 12, 2007 5:32 AM
> To: CentOS mailing list
> Subject: Re: [CentOS] ntpd
>
> On 12/12/2007 05:50, Jason Pyeron wrote:
> > I am running a server inside of VMWare, and the clock gains ~30 seconds
> > every 1000 seconds or 1.03X.
> >
> > /etc/ntp.conf:
> >
> > server time.intranet.pdinc.us maxpoll 7
> >
> > Ideas? If I cannot get ntpd working, then I will have to resort to a cron
> *
> > * * * * rdate -s time.intranet.pdinc.us
>
> I would love to see some clear, accurate guidance from anyone regarding
> time synchronisation within Linux VMs under VMware. From what I've been
> able to gather, VMware recommend that you disable any in-guest external
> synchronisation (ntp, windows time etc) and use vmware-tools to sync the
> time. For now the approach seems to involve trying random kernel boot
> options and a lot of reboots until you find something that works.
>
> I'd be happy to have my understanding of this issue clarified!
>
> cheers
> Luke
>
> Luke,
> We have had similar problems with vm's running fast. I was under the same
> impression that you were about
> the recommended method to sync time. But after working the issue with
> vmware for several months, they backed
> down on their recommendation and stated that they did not recommend using
> both methods togethter: syncing with host AND ntpd.
> They said either would be fine, not both. This didnt entirely fix my
> problem -- still runs a second or two fast, but much better than before.

I think it is worth trying the kernel-vm (100Hz kernel). It may
rectify the time issue you are experiencing. For details, see:

http://bugs.centos.org/view.php?id=2189

Akemi
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 12-12-2007, 01:23 PM
"Jason Pyeron"
 
Default ntpd

Sorry it was late.

Centos 3.x up2date and Centos 4.x up2date all use identical ntp.conf files

> -----Original Message-----
> From: centos-bounces@centos.org
> [mailto:centos-bounces@centos.org] On Behalf Of Tru Huynh
> Sent: Wednesday, December 12, 2007 4:50
> To: CentOS mailing list
> Subject: Re: [CentOS] ntpd
>
> On Wed, Dec 12, 2007 at 01:24:23AM -0500, Jason Pyeron wrote:
> > >
> > > I am running a server inside of VMWare, and the clock gains
> > > ~30 seconds
> > > every 1000 seconds or 1.03X.
> >
> > ...
>
> What CentOS, kernel version?
>
> Maybe a better followup to the centos-virt mailing list...
>
> >
> > > Ideas? If I cannot get ntpd working, then I will have to
> > > resort to a cron *
> > > * * * * rdate -s time.intranet.pdinc.us
> > >
> >
> >
> > ntpdc -p
> >
> > remote local st poll reach delay
> offset disp
> >
> ================================================== ============
> =========
> > =time 0.0.0.0 3 64 1 0.00046
> -34.34546 7.93799
> > =LOCAL(0) 127.0.0.1 10 64 1 0.00000
> 0.000000 7.93752
> > =time2 0.0.0.0 3 64 1 0.00040
> -34.33556 7.93799
> > =time3 0.0.0.0 3 64 1 0.00050
> -34.33738 7.93799
> >
>
> why don't you configure ntpd to an external server?
>
> > ntpdc -c sysinfo
> >
> > system peer: 0.0.0.0
> > system peer mode: unspec
> > leap indicator: 11
> > stratum: 16
> > precision: -16
> > root distance: 0.00000 s
> > root dispersion: 0.00099 s
> > reference ID: [0.0.0.0]
> > reference time: 00000000.00000000 Thu, Feb 7 2036
> 1:28:16.000
> > system flags: auth monitor ntp kernel stats
> > jitter: 0.000015 s
> > stability: 0.000 ppm
> > broadcastdelay: 0.007996 s
> > authdelay: 0.000000 s
> >
> >
> > But still no clock setting...
> >
> >
> > By the time I wrote the above:
> >
> > st poll reach delay offset disp
> > =======================================
> > 3 64 37 0.00058 -52.85483 0.43922
> > 10 64 37 0.00000 0.000000 0.43831
> > 3 64 37 0.00034 -52.79517 0.43925
> > 3 64 37 0.00055 -52.80582 0.43925
> >
> >
> no issue here:
> [tru@centos5-i386-vm ~]$ date
> Wed Dec 12 10:46:02 CET 2007
> [tru@centos5-i386-vm ~]$ sudo ntpdc -p
> remote local st poll reach delay offset disp
> ================================================== ============
> =========
> =LOCAL(0) 127.0.0.1 10 64 1 0.00000
> 0.000000 2.81735
> =ntp.pasteur.fr 157.99.90.56 1 64 1 0.00131
> 0.004765 2.81740
> [tru@centos5-i386-vm ~]$ ntpdc -p
> remote local st poll reach delay offset disp
> ================================================== ============
> =========
> =LOCAL(0) 127.0.0.1 10 64 1 0.00000
> 0.000000 2.81735
> =ntp.pasteur.fr 157.99.90.56 1 64 1 0.00131
> 0.004765 2.81740
> [tru@centos5-i386-vm ~]$ ntpdc -c sysinfo
> system peer: 0.0.0.0
> system peer mode: unspec
> leap indicator: 11
> stratum: 16
> precision: -20
> root distance: 0.00000 s
> root dispersion: 0.00055 s
> reference ID: [73.78.73.84]
> reference time: 00000000.00000000 Thu, Feb 7 2036 7:28:16.000
> system flags: auth monitor ntp kernel stats
> jitter: 0.000000 s
> stability: 0.000 ppm
> broadcastdelay: 0.003998 s
> authdelay: 0.000000 s
> [tru@centos5-i386-vm ~]$ uname -a
> Linux centos5-i386-vm.bis.pasteur.fr 2.6.18-53.1.4.el5vm #1
> SMP Thu Dec 6 11:09:34 EST 2007 i686 athlon i386 GNU/Linux
> [tru@centos5-i386-vm ~]$ ntpdc -p
> remote local st poll reach delay offset disp
> ================================================== ============
> =========
> =LOCAL(0) 127.0.0.1 10 64 17 0.00000
> 0.000000 0.96858
> *ntp.pasteur.fr 157.99.90.56 1 64 17 0.00131
> 0.004765 0.96953
> [tru@centos5-i386-vm ~]$
>
> Cheers,
>
> Tru
> --
> Tru Huynh (mirrors, CentOS-3 i386/x86_64 Package Maintenance)
> http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xBEFA581B
>


_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 12-12-2007, 01:26 PM
"Jason Pyeron"
 
Default ntpd

> > On 12/12/2007 05:50, Jason Pyeron wrote:
> > > I am running a server inside of VMWare, and the clock
> gains ~30 seconds
> > > every 1000 seconds or 1.03X.
>
> I think it is worth trying the kernel-vm (100Hz kernel). It may
> rectify the time issue you are experiencing. For details, see:
>
> http://bugs.centos.org/view.php?id=2189
>

Great for our 2.6 but what about our legacy machines under 2.4?


-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
- -
- Jason Pyeron PD Inc. http://www.pdinc.us -
- Sr. Consultant 10 West 24th Street #100 -
- +1 (443) 269-1555 x333 Baltimore, Maryland 21218 -
- -
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

This message is for the designated recipient only and may contain
privileged, proprietary, or otherwise private information. If you
have received it in error, purge the message from your system and
notify the sender immediately. Any other use of the email by you
is prohibited.



_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 12-12-2007, 01:51 PM
"Brian Mathis"
 
Default ntpd

On Dec 12, 2007 12:50 AM, Jason Pyeron <jpyeron@pdinc.us> wrote:
> I am running a server inside of VMWare, and the clock gains ~30 seconds
> every 1000 seconds or 1.03X.
>
> I need to keep the drift under the magic 1000 limit that ntpd kills its
> self, but despite setting maxpoll really low I get:
>
> Dec 11 23:58:14 host ntpd[4909]: kernel time discipline status change 41
> Dec 11 23:59:17 host ntpd[4909]: kernel time discipline status change 1
> Dec 11 23:59:17 host ntpd[4909]: time correction of -1123 seconds exceeds
> sanity limit (1000); set clock manually to the correct UTC time.
>
>
> /etc/ntp.conf:
>
> server time.intranet.pdinc.us maxpoll 7
>
> Ideas? If I cannot get ntpd working, then I will have to resort to a cron *
> * * * * rdate -s time.intranet.pdinc.us
>


Do not use ntp to sync time on the guest OS. Sync using ntp on the
HOST, and then use the vmware tools to sync in the guest. I have
pursued this issue many times, and that is the best answer.

Then update your kernel boot parameters and add:
clock=pit # for kernels less than 2.6
OR
clocksource=pit # for kernels 2.6.16 and later

There is far more than you ever wanted to know about vmware time syncing here:
http://www.vmware.com/pdf/vmware_timekeeping.pdf
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 12-12-2007, 02:41 PM
"Akemi Yagi"
 
Default ntpd

On Dec 12, 2007 6:26 AM, Jason Pyeron <jpyeron@pdinc.us> wrote:
> > > On 12/12/2007 05:50, Jason Pyeron wrote:
> > > > I am running a server inside of VMWare, and the clock
> > gains ~30 seconds
> > > > every 1000 seconds or 1.03X.
> >
> > I think it is worth trying the kernel-vm (100Hz kernel). It may
> > rectify the time issue you are experiencing. For details, see:
> >
> > http://bugs.centos.org/view.php?id=2189
>
> Great for our 2.6 but what about our legacy machines under 2.4?

If I'm not mistaken, the 2.4 kernel runs at 100Hz by default.

Akemi
_______________________________________________
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