unresolved SUMMARY : console/machine slow while swapping or with a bit of load

From: Amol Karnik (amol@memcad.com)
Date: Sun Feb 15 1998 - 13:32:39 CST


Hi folks,

sorry for the delay in the summary posting...but the problem remains
unresolved

my original question was :
--------------------------
 
I'm totally frustrated here and have no idea what to do, or how to
troubleshoot this.

i work on the console, on an Ultra 2 running Solaris 2.5.1
with 512Megs of RAM and 1.6Gigs swap space on /tmp.

There are two other people who also share this dual processor
machine with me. They work on xterminals which are connected to
this machine. One of those users, who works an xterm, runs
a solver job which swaps out a lot , and hence uses only aroung 175Megs
of RAM. These two persons are able to work just fine on their
xterms while this job is running. However I cannot work on the machine
at all. The console is very slow and i cant change workspaces and my
mouse is extremely slow, you cant imagine the frustration here. I can
hear the
machine swapping whole day, and am unable to work at all.

I dont know whats wrong or what i can do to resolve this problem. Why is
this machine having so many problems, even though it is such a kick ass
machine, with 2 cpu's and so much RAM? Do i have to change some kernel
settings?
do i need some patches? Its quite a new machine, bought in August 97.

at this point, i can use any bit of help that you can give. if you need
more info, like output of top, vmstat , iostat etc, please let me know
and i can email you directly.

------------------------------------

Replies and suggestions :
------------------------

I received a few replies from some friendly people with good advice.

It was suggested to apply all recommed patches to the machine. I applied
the latest patch cluster for solaris2.5.1 from Sun. It didnt make any
difference.

a few folks asked me to renice the processes. But thats not possible
as i cant be renicing others process the whole day! although i do
bind these big jobs to only one cpu sometimes, when i'm totally
frustrated.

most people asked me to look at vmstat and check the values for the
sr (scan rate field). I loaded up the machine and checked. They
fluctuated
from 0 to 450....mostly around 250-300, and 0 at all other times.
i have no idea what this means though, only that it means its paging a
lot.
why? i have 512 Megs of RAM. Other single CPU machines with less RAM and
only
one CPU do not show this strange problem.
 
people suggested looking at the book Sun Performance and Tuning by
Adrian Cockcroft.
I'll take a look at soon, but since i'm not really a sys admin...just
find
myself being one... dont really understand these sys tuning parameters!

much thanks to the ppl who responded!
       
Robin Landis (robin.landis@exim.gov)
Rahul Roy (uroy@eadev1.vanguard.com)
Ning Zhang (btinz@ui.uis.doleta.gov)
Harry Levinson (levinson@ll.mit.edu)
Kevin Sheehan (Kevin.Sheehan@uniq.com.au)
Matt Reynolds (reynolmd@aston.ac.uk)
Nicholas Masika (Nicholas_Masika@mfi.com)

regards,

amol

-- 
-----------------------------------------------------
Amol Karnik          		   
Development Engineer           amol@memcad.com
Microcosm Technologies, Inc.   (617) 225-0094 x248
215 First St., Suite #2D       (617) 621-7838 FAX
Cambridge MA, 02142            http://www.memcad.com
-----------------------------------------------------



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:12:31 CDT