FAQ

-----Original Message-----
From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On
Behalf Of Mailing List
Sent: Wednesday, April 13, 2011 16:23
To: CentOS mailing list
Subject: Re: [CentOS] CentOs 5.6 and Time Sync

/etc/ntp;

restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1
server 0.centos.pool.ntp.org
server 1.centos.pool.ntp.org
server 2.centos.pool.ntp.org
server 127.127.1.0 # local clock
fudge 127.127.1.0 stratum 10
driftfile /var/lib/ntp/drift
keys /etc/ntp/keys

There is no /etc/ntp/ntpservers

/etc/ntp/step-tickers is an empty file.

/var/lib/ntp/drift;
-65.219

I have no /var/log/ntpd.log

/varlog/messages; This is the log using stock updated kernel.

Apr 12 03:32:35 Server ntpd[2797]: synchronized to LOCAL(0), stratum 10
Apr 12 03:33:36 Server ntpd[2797]: synchronized to 173.9.142.98,
stratum 2
Apr 12 15:51:56 Server ntpd[2797]: time reset +43208.248852 s
Wow! That is a big jump.
Apr 12 15:51:56 Server ntpd[2797]: kernel time sync enabled 0001
Apr 12 15:56:03 Server ntpd[2797]: synchronized to LOCAL(0), stratum 10
Apr 12 15:56:26 Server ntpd[2797]: synchronized to 169.229.70.183,
stratum 3
Apr 12 16:00:22 Server ntpd[2797]: synchronized to 173.9.142.98,
stratum 2
Apr 12 16:16:59 Server ntpd[2797]: synchronized to 169.229.70.183,
stratum 2
Apr 12 16:16:57 Server ntpd[2797]: time reset -1.830305 s
Apr 12 16:20:27 Server ntpd[2797]: synchronized to LOCAL(0), stratum
10

<SNIP log of ntpd jumping from server to server (fairly often) including
LOCAL host>

It seems that the connections to the external ntp servers are not good
enough to keep you off LOCAL, and once on local you will drift at the
rate the system last had, and that drift rate can be quite large when
the system is first trying to come into sync. (and often quite a bit
larger than the steady state drift rate once synced)
Selinux is disabled, and just a note also. This is a stock install
of
of ntp. I never had to do any fudging with it cause it just worked up
until the update.

I also have no /var/log/audit/audit.log.

tia.

Brian
We still don't know why the machine is losing time, but it might help to
have some more data to compare with
IIRC you indicated you had two other servers in your environment that
were still keeping time good...
I would suggest adding something like:
echo "server myotherserver" >> /etc/ntp.conf
echo "restrict myotherserver mask 255.255.255.255 notrap" >>
/etc/ntp.conf

you may also have to add restrict a line on "myotherserver" such that
your "timeloosingserver" can get info, i.e. on myotherserver
echo "restrict timeloosingserver mask 255.255.255.255 nomodify notrap"
/etc/ntp.conf
[please evaluate the above restrict lines to verify they are good enough
security for your environment, I am doing them from memory]

so that you have a local host which is not bouncing all over the place,
with respect to connectivity, to check against.

Search Discussions

Discussion Posts

Previous

Follow ups

Related Discussions

Discussion Navigation
viewthread | post
posts ‹ prev | 12 of 37 | next ›
Discussion Overview
groupcentos @
categoriescentos
postedApr 13, '11 at 7:35a
activeMay 12, '11 at 1:06p
posts37
users13
websitecentos.org
irc#centos

People

Translate

site design / logo © 2022 Grokbase