RHEL 4 local time syncproblem

bobbera · 05-26-2008, 04:17 AM

Hi . We've been running on remote site RHEL 4 systems , they are clients are to be synchronized against some time server . When this server has a problem , being rebooted etc. , Linux machines start to adjust time to themselves . It causes the situation when Linux host acts as a local timeserver .
The question : How to configure the NTP mechanism to not jump too far ahead in the future ?

Thanks . Vlad .

unSpawn · 05-26-2008, 05:40 AM

Wouldn't configuring another two hosts as backup NTP servers be the next thing to look at instead? Wrt perf and security AFAIK it could be any box as long as it can be polled from subnets and has (limited) access to the 'net.

bobbera · 05-26-2008, 07:40 AM

Unfortunatelly we cannot manage there ntp servers locally - it's a custom site .
So we need whatever solution at local linux level .
Thanks .

unSpawn · 05-27-2008, 07:24 AM

What does "custom site" mean? Can't you install software? Do you only have user access to applications?

ncsuapex · 05-27-2008, 09:39 AM

Not sure if this will fix your problem but I had similar issues with time drifting too far off and changed this line in /etc/sysconfig/ntpd
I was using CentOS5.1 but it may be the same for RHEL4

from:
OPTIONS="-u ntp:ntp -p /var/run/ntpd.pid"

to

OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid"

just added the -x flag and so far the time has not drifted. Read the man pages carefully for details on the -x flag to see if it makes sense for your situation.