[CentOS] CPU utils almost 100%

fabian wrote:
>> 2009/7/5 fabian <fabian at baladia.gov.kw>
>>
>>> i notced recently that the cpu utilization peaks to abt 100 % at 4 am
>>> every day and becomes normall at 10 am
>>>
>>>
>>> cpu 4.5%us   2.3% sy  0.0%ni 2% id   95% wa
>>>
>>> notice the 95% wa
>>>
>>>
>> It looks like you might be misreading the idle % for CPU activity.  A 95%
>> idle shows the system is not doing much.
>>
> 
> so sorry abouyt my typing
> 
> its cpu==>4.5%us
> sy==> 2.3%
> ni==> 0.0%
> id==> 2 %
> wa==> 95%
> 
> 
> so the wa=95 %
> 
> this starts about 4 am and stops about 10 am
> then the CPU idle time is always between 90% to 99%

Wait means the kernel is waiting for some device i/o command(s) to complete. 
The CPU is idle but can't do anything useful without the results from the 
device, probably disk or network.  Starting at 4 am makes the 'updatedb'run that 
builds the database for the locate command a likely culprit.  Do you have a lot 
of files, slow disks, or perhaps some network mounts that are included?

-- 
   Les Mikesell
    lesmikesell at gmail.com