Jeff:
 
I was running my workstation with no swap enabled.
 
I waited about 10 minutes for my various applications to speed up again (they didn't) after attempting to interact with them and killed all the uml instances.  At that point, all my applications (basically broswer instances and terminal sessions running under KDE) immediately regained their responsiveness and my %wa as reported by vmstst went from 96% down to 0%.
 
Chris Marshall

Jeff Dike <jdike@addtoit.com> wrote:
On Tue, Jun 05, 2007 at 03:29:14AM -0700, Christopher Marshall wrote:
> I left a set of 4 UML instances running overnight and noticed that
> in the morning my computer was not very responsive (every application
> I tried to interact with seemed slow). vmstat reported 96% IO wait
> (wa%).

Offhand, I would guess that the UMLs pushed everything else out to
swap, and when you came in the next morning, it all had to be swapped
back in, hence the lagginess and high IO wait time.

Jeff

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Work email - jdike at linux dot intel dot com