cancel
Showing results for 
Search instead for 
Did you mean: 

Service time vs. Wait time

Christof Schoeman
Frequent Advisor

Service time vs. Wait time

Hi

Can anybody explain to me the difference between average service time and average wait time, as reported by collect?

Also, how does this relate to the active queue and the wait queue?

Hope you can help.
3 REPLIES
Victor Semaska_3
Esteemed Contributor

Re: Service time vs. Wait time

Did you look at the manpage for collect. In the 'Disk Section' it gives explanations of those fields.

Vic
There are 10 kinds of people, one that understands binary and one that doesn't.
Christof Schoeman
Frequent Advisor

Re: Service time vs. Wait time

Thanks

Just to make sure I understand the man page correctly:

- When an I/O is issued (by whatever), it goes into the wait queue and the wait timer is started.
- When the I/O reaches the front of the wait queue, the wait timer is stopped, giving us our wait time.
- The I/O is then sent to disk, the service timer started and the I/O goes into the active queue.
- When the disk returns the result, the service timer is stopped, giving us our service time, and the I/O is taken off the active queue.

Does that sound right?
Victor Semaska_3
Esteemed Contributor

Re: Service time vs. Wait time

Christof,

That sounds right to me.

Vic
There are 10 kinds of people, one that understands binary and one that doesn't.