[Orca-users] RE: FW: Capacity Planning ... PRIORITY_PAGING and MORE

[Edwards, Mark]

e-Ken - Thanks! this is really good stuff! I'll take a close look at this.

Mark-e

:g)

Mark P. Edwards 
Online Architect 
Pacific Access IT
MarkE at pacificaccess.com.au
+61 3 9281 3522
+61 407 322 033


-----Original Message-----
From: Ken Gottry [mailto:ken at gottry.com]
Sent: Friday, 10 November 2000 5:44
To: orca-discuss at egroups.com
Subject: Re: [orca-discuss] FW: Capacity Planning ... PRIORITY_PAGING
and MORE


Hi Mark-
Before you add RAM be sure you have priority_paging turned on. Priority
paging is to main memory what Harvard cache algorithm is to L1 cache.
(differentiates between data and code when it comes to paging).  I had a
situation once where I was getting 10000 pgscan/sec. I increased RAM
from 3GB to 6GB, no impact on scanrate. I increased from 6GB to 10GB, no
impact on scanrate. I called Adrian Cockcroft and he told me to turn on
priority_paging. I did so and scanrate dropped to 0, CPU utilization
dropped from 80% to 10%. We cancelled our order for the E10000 :-)

The attached priority_paging PDF is from Rich McDougall's Sun website.
(http://www.sun.com/sun-on-net/). Explains how to turn on PP. Lots of
other good performance stuff on this website.

If using Solaris 2.6 be sure to apply the required patch. PP is part of
Solaris7 but is set to false by default. I've been told that Sun made
the PP default true with Solaris 8.

You also might want to grab a copy of proctool from
http://www.sunfreeware.com/ and a copy of memtool from
http://playground.sun.com/pub/memtool/. These give you a more granular
picture of what each process is doing to your system.

Enjoy,
e-Ken

PS - as long as I'm throwing performance info your way, here's some
other "gotta-haves".  Jens Voeckler's Solaris TCP tuning website
(http://www.rvs.uni-hannover.de/people/voeckler/tune/EN/tune.html).
Sun's "Solaris Tunable Parameters" book #806-4015 which can be
downloaded from Sun docs
(http://docs.sun.com/ab2/coll.707.1/SOLTUNEPARAMREF/@Ab2PrintSelect?Ab2Lang=
C&Ab2Enc=iso-8859-1)

PS - if you're ever asked to do Security tuning, another "gotta-have" is
SANS Institute's Securing Solaris Step-by-Step, downloaded for a fee
from either SANS Store (http://www.sansstore.org/) or maybe from SANS
home site (http://www.sans.org/).



"Edwards, Mark" wrote:
> 
> > Hi,
> >
> > I have been asked to produce a capaity plan for one of the platforms
that
> > our company runs, however the platform appears to be RAM bound at the
> > moment. (Page Scan rates high and residency times low at times of peak
> > demand). I am also noticing an potential issue with CPU usage. These
> > servers have 6 CPU's on board and 5Gb RAM, however looking at the
> > description you have given of the 'CPU usage' graph - particuarly where
> > you say:
> >
> > "If idle time is always low, check the number of processes in the run
> > queue. More, or faster, CPUs may be necessary. If user CPU time is
> > commonly less than system CPU there may be problems with the system set
> > up."
> >
> > I am noticing a consistent difference between the user and system CPU
> > usage where the user CPU usage indeed appears to be less than the system
> > CPU usage. Might this be additional evidence of a RAM bound state - high
> > amounts of VM swappage going on?
> >
> >  <<o___usr_pct,__sys_pct,__100_-_usr_pct_-_sys_pct-weekly.png>>
> > <<o___scanrate-daily.png>>  <<o___page_rstim-daily.png>>
> >
> > Please forgive me for asking this of you, but I am a tad new to capacity
> > planning and graph interpretation, and looking for some assistance...
> >
> > Mark
> >
> > Mark P. Edwards
> > Pacific Access IT
> > MarkE at pacificaccess.com.au
> > +61 3 9281 3522
> > +61 407 322 033
> >
> 
> 
>   ------------------------------------------------------------------------
>                                                                  Name:
o___usr_pct,__sys_pct,__100_-_usr_pct_-_sys_pct-weekly.png
>    o___usr_pct,__sys_pct,__100_-_usr_pct_-_sys_pct-weekly.png    Type: PNG
Image (image/x-png)
>                                                              Encoding:
base64
> 
>                              Name: o___scanrate-daily.png
>    o___scanrate-daily.png    Type: PNG Image (image/x-png)
>                          Encoding: base64
> 
>                                Name: o___page_rstim-daily.png
>    o___page_rstim-daily.png    Type: PNG Image (image/x-png)
>                            Encoding: base64



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