🚀 go-pugleaf

clangfor@mach1.wlu.ca (Carl Langford s) writes:

>We have a S81 running ptx v1.3. Once in a while, the system becomes quite
>sluggish. sar shows that the system disk (zd0) is 100% busy. The disk
>contains /, /usr and two swap partitions. sar also shows that there is no
>swapping on this system. /tmp is mounted as a separate partition on a 
>different disk. We have no user accounts on /usr, and, as far as we can
>tell, have no applications using / or /usr except for normal system
>activity. Can anyone provide some suggestions on what other things we should
>look for? The machine has been set up for timesharing (as opposed to
>commercial), has 14 processors and 144 meg of RAM. It typically supports 
>100+ users and the slowdown does not seem to be related to user load.

Swapping is not the only thing that would bring a system to its knees.
You might check the monitor program for excessive paging.  If this is
the case then your vmtune resident set size might be set too small.

You also might want to move one of you swap devices to another drive.  I
typically only have one swap device per spindle.

If you still have problems, you can also move /usr to a different drive.
I would bet that it is the paging problem though.

--
Robert Winter
Sequent Computer Systems
Costa Mesa, CA
winter@sequent.com

disclaimer: Opinions expressed here are my own.  Use at your own risk,
etc. etc.