CentOS - Jan 2008 - The iostat command

Hi All,

I am learning iostat command to understand disk I/O statistics.

We have 2 Centos 4 servers running where oracle is installed.We
installed them 2 weeks ago. @ that time, These Servers performed well.
But, Now We have come to know that these 2 Machines are quite slow
when comparing to the first week.

So, Some say, run iostat to see statictics. I am not familiar with comamnd well.

 I found below url

redhat.com/docs/manuals/enterprise/RHEL-4-Manual/admin-guide/s1-resource-rhlspec.html

And, I  have still not understood it fully.

Could you pls advice me , If you have experience with iostat?

In adition to that, What are the other tools I can use?

I have already used,

top , vmstat commands

Hope to hear from you.


-- 
Thank you
Indunil Jayasooriya

Indunil Jayasooriya wrote:
> Hi All,
>
> I am learning iostat command to understand disk I/O statistics.
>
> We have 2 Centos 4 servers running where oracle is installed.We
> installed them 2 weeks ago. @ that time, These Servers performed well.
> But, Now We have come to know that these 2 Machines are quite slow
> when comparing to the first week.
>
> So, Some say, run iostat to see statictics. I am not familiar with comamnd
well.
>
>  I found below url
>
>
redhat.com/docs/manuals/enterprise/RHEL-4-Manual/admin-guide/s1-resource-rhlspec.html
>
>   
as the page says, `man iostat` for more information

i typically run something like

# iostat -x 5

and ignore the first sample.. every 5 seconds this will output 
information on disk IO by drive volume.   I find the await a 
particularly important, as its the amount of time disk IO operations are 
staying queued waiting for the drive, if this gets up tnio the 1000mS 
range you have a serious bottleneck

you said Oracle.    to manage and maintain a production Oracle database 
server, you need an experienced Oracle Data Base Administrator ("DBA")
who can optimize and tune and maintain the database.   such a person 
will be very familiar with tracking query and tablespace IO statistics, 
identifying bottlenecks and restructuring things to achieve optimal 
performance