iostat on solaris


 
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# 1  
Old 10-07-2009
iostat on solaris

Friends.
I have to compare iostat -x output with a tool on solaris. Now there is column called wait in the output field which is showing zero. Now, in order to create some load on my system this is what i am doing



I am creating a file using dd command , the size of which is just half of the RAM size.

Now using the following code to create a forever loop
Code:
#!/bin/sh

while [ i -lt 2 ]
do
cp <file-name> /
done

Now however whenever i see the wait column in iostat -x , it always showing 0. Is this a issue with iostat or my understanding is wrong in this regard.
.
# 2  
Old 10-07-2009
just post the output of iostat for us to see... if the drive can handle the io, the waits will always be zero...

from the manpage:
Code:
     wait      average number of transactions waiting for service
               (queue length)

               This is the number of I/O operations held  in  the
               device  driver queue waiting for acceptance by the
               device.

# 3  
Old 10-07-2009
Then how do i increase the wait time. ??
# 4  
Old 10-07-2009
start a lot of dd processes that write to disk for example... or maybe you can use sunvts...
# 5  
Old 10-07-2009
ok

very very thanks man
# 6  
Old 10-08-2009
Hey thanks man. It worked out. I mean i ran 7 dd commands and finally i saw my wait queue value going up. but the tool sunvts has a lot to be desired still. But anyway. alls well that ends well.
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