topas - computational memory 95% : Any Impact? Post: 302493000

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Operating Systems AIX topas - computational memory 95% : Any Impact? Post 302493000 by bakunin on Wednesday 2nd of February 2011 05:07:57 AM

02-02-2011

Registered User

Quote:

Originally Posted by zxmaus

well let me disagree here ... computational memory above 85% is never a good idea

Depending on the exact circumstances this is true in most cases, of course. I was a bit too general in my answer.

@panchpan:

Your vmstat output shows several things. First let's look at the memory situation: The "avm" and "fre" columns are displayed in pages of 4k each. You roughly have 5.5 mio pages available ( 5.5 mio x 4k ~ 22GB ) and of these are ~25k pages (~100MB) not used by the system at all. This might be a bit on the light side as a reserve and - as zxmaus has pointed out - you should watch and monitor the system closely to proactively find out probably bottlenecks. Even if you don't have one you might be close to getting one, as zxmaus has already suggested.

On the other hand your "pi" and "po" columns (page in / page out) are constantly zero, which means there is no paging going on yet. Your "vmstat -s" output shows some paging activity, which should be investigated. Issue the same command over the next days once a day and compare the numbers in it. If they remain constant there is nothing to worry, if they increase then paging is happening somewhere and it will be worth it to find out what causes it.

You might also want to issue "vmstat -v" and watch if there are I/O-buffers lacking. (there are also several threads here discussing exactly this)

The CPU part of your vmstat output shows relatively high idle values (id). "us", "sy", "id" and "wa" are percentage values, depicting the time the CPU(s) spend working on user code (basically programs), system code, idling and waiting (for I/O). High waiting numbers mean there are I/O-bottlenecks, because there would be programs ready to do something, which they cannot do because they cannot read their data. There is no such thing in your output, which is a sign of healthiness in this regard.

Notice the "ec" column: this is also a percentage value and signifies the "entitled [CPU] capacity consumed". Your system is allowed to use 2 CPUs and of these about 25% on average (0.5 CPUs) is used. If this value is constantly below 50% you might want to reduce the entitlement to 1 CPU, if it constantly nears 100% you might want to add a CPU to the LPAR configuration. But before suggesting something in this direction first monitor closely over a longer time. There is no sense in doing performance optimization from a single seconds-long snapshot.

I hope these tips help.

bakunin

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LEARN ABOUT SUSE

substrate

substrate(6x)							XScreenSaver manual						     substrate(6x)

NAME

       substrate - Grow crystal-like lines on a computational substrate

SYNOPSIS

       substrate  [-display  host:display.screen]  [-foreground  color]  [-background  color] [-wireframe] [-max-cycles cyclecount] [-growth-delay
       delayms] [-initial-cracks numinitial] [-max-cracks nummax] [-sand-grains numgrains] [-circle-percent circlepercent] [-fps]

DESCRIPTION

       Lines like crystals grow on a computational substrate.  A simple perpendicular growth rule creates intricate city-like structures.  Option-
       ally, cracks may also be circular, producing a cityscape more familiar to places for which city planning is a distant, theoretical concern.

       Ported from the code by j.tarbell at http://complexification.net

OPTIONS

       substrate accepts the following options:

       -wireframe (Default: False)
	       Don't draw sand-painting colored effects, only make a wireframe.

       -max-cycles cyclecount (Default: 10000)
	       Maximum number of growth cycles before restarting.  The higher this is, the more complex the art.

       -growth-delay delayms (Default: 18000)
	       Delay in ms between growth cycles.  More delay, slower (but smoother and less CPU intensive) art.

       -initial-cracks numinitial (Default: 3)
	       Initial number of cracks in the substrate

       -max-cracks nummax (Default: 100)
	       Maximum number of cracks in the substrate at a single time

       -sand-grains numgrains (Default: 64)
	       Number of sand grains dropped during coloring.  More grains cause a denser colour but use more cpu power.

       -circle-percent circlepercent (Default: 0)
	       The percentage of the cracks will be circular.

       -fps    Display the current frame rate and CPU load.

ENVIRONMENT

       DISPLAY to get the default host and display number.

       XENVIRONMENT
	       to get the name of a resource file that overrides the global resources stored in the RESOURCE_MANAGER property.

SEE ALSO

       X(1), xscreensaver(1)

COPYRIGHT

       Copyright (C) 2003 by J. Tarbell (complex@complexification.net, http://www.complexification.net).

       Ported to XScreensaver 2004 by Mike Kershaw (dragorn@kismetwireless.net)

AUTHOR

       J. Tarbell <complex@complexification.net>, Jun-03

       Mike Kershaw <dragorn@kismetwireless.net>, Oct-04

X Version 11							5.10 (07-Sep-2009)						     substrate(6x)