How to start SSHD in high priority?

[Christopher Chan]

howard chen wrote:
> Hey,
> 
> On Wed, Feb 11, 2009 at 10:49 PM, Chan Chung Hang Christopher
> <christopher.chan at bradbury.edu.hk> wrote:
> 
>> Are you sure that your login problems are due to mysql pegging cpu? It
>> could also be due to heavy disk i/o (aka swapping) and if it is,
>> changing priorities makes zero difference.
>>
> 
> Why? If priority is reduced => chance of using I/O also reduced
> 


As another poster has already explained, setting a different priority 
has zero bearing on disk i/o since it is only for cpu processing time. 
There is no provision for giving a particular process more privileges in 
disk i/o as far as I know too.

What you really need to do is follow the suggestion of another poster 
and run 'vmstat 1'.

Look at the last number which should correspond to wa. High wa numbers 
mean that the box is suffering from a i/o bottleneck. That might also 
mean high id numbers (id is the second last column and stands for cpu 
idle) which would mean the box only suffers i/o bottlenecks which is 
preventing optimal use of available cpu power.

If you have high wa numbers and low id numbers (maybe even 0) you are 
suffering from both lack of cpu processing power to a degree and an i/o 
bottleneck.

If you have both low id and wa numbers, you need more cpu processing 
power...especially if id is 0 and wa is still low. The box is maxxed out.