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
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- - - - 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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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
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
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 delayoffset 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
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
-----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.
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
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:
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.
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:
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
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
-
Akemi Yagi -
Blackburn, Marvin -
Brian Mathis -
Jason Pyeron -
Luke Dudney -
Tru Huynh