top shows my system as having 50% iowait (leading to very little cpu idle) 
and 900M swap im use (I have 1GB physical RAM)

How do I go about identifying which processes are using the 900M swap 
space? Also, which processes are the cause/effect of the 50% iowait?

Thanks

G'Day,

On Wed, 3 Dec 2003, Vikas Agnihotri wrote:

> top shows my system as having 50% iowait (leading to very little cpu idle)
> and 900M swap im use (I have 1GB physical RAM)
>
> How do I go about identifying which processes are using the 900M swap
> space? Also, which processes are the cause/effect of the 50% iowait?


Processes using swap: try "/usr/ucb/ps -aux" or "prstat -s size" (or
"ps -eo pid,vsz,args") and looking at their size. For more details try
the MemTool package.

Processes causing io: truss or "prex -k" can be used, but aren't as user
friendly as ps. I'm working on a freeware tool to add a %I/O column to a
"ps -ef" output (I posted it to comp.unix.solaris about 18 hours ago :)

Brendan Gregg

[Sydney, Australia]

Vikas Agnihotri wrote:

> top shows my system as having 50% iowait (leading to very little cpu idle)
> and 900M swap im use (I have 1GB physical RAM)
> 

This may not be the case for you, but last time I saw 2 CPUs on a 4 CPU box
get completely tied up in IOWait, a disk had failed.

> How do I go about identifying which processes are using the 900M swap
> space? Also, which processes are the cause/effect of the 50% iowait?
> 

Pressing 'o' in top will allow you to change the sort field, then I suppose
'size' is the best field to sort on to display total temporary store used. 
ps -o vsz should work too, can't confirm this as I have GNU ps installed :)
-- 
Graham Lee
Wadham College
Oxford