[CentOS] NTPD ?

[Paul Heinlein]

On Thu, 24 May 2007, Scott Lamb wrote:

> On May 24, 2007, at 10:36 PM, jarmo wrote:
>
>> Have used Centos 5 now couple of weeks and started to find pieces 
>> on places, ie. found logs :D
>> 
>> Now, these ntpd errors strances me. Anyone else getting these?
>>
>>  Errors
>>    frequency error 500 PPM exceeds tolerance 500 PPM: 1 time(s)
>>    frequency error 503 PPM exceeds tolerance 500 PPM: 1 time(s)
>>    frequency error 504 PPM exceeds tolerance 500 PPM: 1 time(s)
>>    frequency error 505 PPM exceeds tolerance 500 PPM: 1 time(s)
>>    frequency error 509 PPM exceeds tolerance 500 PPM: 3 time(s)
>>    frequency error 512 PPM exceeds tolerance 500 PPM: 203 time(s)
>
> That means that your clock is drifting too badly for ntpd to 
> compensate by slewing time, and it's had to step instead. So time on 
> your machine is discontinuous and possibly stepping backwards. You 
> can find some more information by searching for "500" in the ntpd 
> manpage.
>
> I think this would be due to bad hardware or a kernel problem.

Or something like a saturated I/O subsystem.

I've got an x86_64 CentOS 5 server with two SATA drives, mirrored with 
software RAID 1. The auditctl ruleset was causing auditd to log like 
crazy, and ntpd was paying the price.

With all the logging going on, the drift was bumping up against the 
500 mark. Once I altered the ruleset, the drift has settled down to a 
reasonable single-digit number.

So you might check to see if top or iostat is reporting a lot of disk 
usage...

-- 
Paul Heinlein <> heinlein at madboa.com <> http://www.madboa.com/