Hi,

I am having an issue with NTP on red hat linux box. When I restart ntp, the server is able to sync with the clocks, (*, + & + ) but after some time (few seconds or 1 min), it's losing back the sync.

Can anyone tell me why its so ? and how can I fix it ?

Not information provided to say anything.

Are you using a ntp pool server or syncing to your own? A few seconds or min is typically not enough time to sync i.e. *,+ or -. Post the output of the command:
ntpq -pn

1 members found this post helpful.

The basics as to "why" usually boil down to too much difference between the system clock to start with, and the NTP daemon. Did you sync your system clock FIRST, before trying to start NTP??? Something like "sntp -s pool.ntp.org"??

And if this is a virtual machine, there are often times patches that MUST be loaded, otherwise the system will drift uncontrollably, no matter WHAT you do.

@Michaelk : Here is ntpq -pn

remote refid st t when poll reach delay offset jitter
==============================================================================
clock01 .GPS. 1 u 2 64 17 35.680 31053.1 12172.9
clock02 .GPS. 1 u 67 64 17 46.185 30814.5 16672.6
clock03 .GPS. 1 u 64 64 17 62.991 30830.5 16633.0



@TB0ne: Yes this is VM. I did sync it using system clock - ntpdate -s pool.ntp.org

So what are you running i.e vmware, virtualbox etc.

It's on ESX host.

A VM requires some configuration changes.

http://kb.vmware.com/selfservice/mic...rnalId=1006427

Please read the "Question Guidelines" link in my posting signature. You're not providing details, and having to keep asking for them over and over isn't too pleasant.

You still don't say what version of Red Hat you're using, whether you're paying for it, or what version of ESX either. Again, as michaelk pointed out, you probably need to perform some changes to your system. And AGAIN, you will ALSO probably have to have a patch from Red Hat and/or VMWare for this to function correctly. Have you contacted either Red Hat or VMware support yet??? You're paying for support, since both are commercial products, and they can advise you about the patches you may need.

Hello there,

The vmware link provided fixed it out. Had to disable the VMware Tools periodic time synchronization.
Working fine now.


And here is the OS config:

Red Hat Enterprise Linux Server release 6.6 (Santiago)
2.6.32-431.29.2.el6.x86_64

ESX 5.1.0

Sorry forgot to post it in previous posts.


Thank you both for the responses.

Probably WON'T be in a while...because....
You're using a fairly old version of ESX, and a dated version of RHEL. Again, ARE YOU PAYING for them??? Because there is a patch you have to load to KEEP NTP running, because it will drift very easily. That patch is available to ESX customers, and to RHEL customers. NTP will sync, and may stay ok for up to a day...but chances are it won't keep running much longer than that, unless you've applied the patch to your ESX.