Alan Stange wrote:
Luke Lonergan wrote:
The "aka iowait" is the problem here - iowait is not idle (otherwise it
would be in the "idle" column).
Iowait is time spent waiting on blocking io calls. As another poster
pointed out, you have a two CPU system, and during your scan, as
iowait time is idle time. Period. This point has been debated
endlessly for Solaris and other OS's as well.
I'm sure the the theory is nice but here's my experience with iowait
just a minute ago. I run Linux/XFce as my desktop -- decided I wanted to
lookup some stuff in Wikipedia under Mozilla and my computer system
became completely unusable for nearly a minute while who knows what
Mozilla was doing. (Probably loading all the language packs.) I could
not even switch to IRC (already loaded) to chat with other people while
Mozilla was chewing up all my disk I/O.
So I went to another computer, connected to mine remotely (slow...) and
checked top. 90% in the "wa" column which I assume is the iowait column.
It may be idle in theory but it's not a very useful idle -- wasn't able
to switch to any programs already running, couldn't click on the XFce
launchbar to run any new programs.
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