Re: High load and iowait but no disk access

On 30-Aug-05, at 12:15, Tom Lane wrote:

> =?ISO-8859-1?Q?R=E9my_Beaumont?= <remyb@medrium.com> writes:
>> The stats of the NetApp do confirm that it is sitting idle.
>
> Really?


>
>>   CPU   NFS  CIFS  HTTP   Total    Net kB/s   Disk kB/s     Tape kB/s
>> Cache Cache  CP   CP Disk   DAFS   FCP iSCSI   FCP  kB/s
>>                                    in   out   read  write  read write
>> age   hit time  ty util                       in   out
>>    2%     0     0     0     139     0     0   2788      0     0     0
>>   3   96%   0%  -   15%      0   139     0     3  2277
>>    2%     0     0     0     144     0     0   2504      0     0     0
>>   3   96%   0%  -   18%      0   144     0     3  2150
>>    2%     0     0     0     130     0     0   2212      0     0     0
>>   3   96%   0%  -   13%      0   130     0     3  1879
>>    3%     0     0     0     169     0     0   2937     80     0     0
>>   3   96%   0%  -   13%      0   169     0     4  2718
>>    2%     0     0     0     139     0     0   2448      0     0     0
>>   3   96%   0%  -   12%      0   139     0     3  2096
>
> I know zip about NetApps, but doesn't the 8th column indicate pretty
> steady disk reads?
Yes, but they are very low.
At 15% usage, it's pretty much sitting idle if you consider that the OS
reports that one of the processor is spending more then 80% of it's
time in IOwait.

Rémy
>
>             regards, tom lane