Re: Memory Performance - When is RAM over committed ?

Hello, Kenneth:

Do you have IBM Performance Tools on your system? (GO LICPGM, then take option 10, Display installed licensed programs.) If so, you can type GO PERFORM and start from there. You can turn on various performance monitors to capture relevant data and then produce various reports from that data. See also:
http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/rzahx/rzahxptrpts.pdf

There are also a number of freely available RedBooks on performance tuning, such as:
http://www.redbooks.ibm.com/abstracts/sg244735.html?Open

Also, iSeries / Operations Navigator (Management Central) can display various performance indicators.
http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/rzaih/rzaih.pdf

See the current IBM System i Work Management Guide in the InfoCenter for current recommendations on page faulting rates.
http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/rzahx/rzahx.pdf

I also recommend this book:
http://www.mc-store.com/5824.html

Although slightly dated, the overall methodology, tools and techniques still apply. Just bear in mind that the System i of today is several orders of magnitude faster than, and has several orders of magnitude more main storage and DASD, than the AS/400 models that were in use when this book first appeared.

HTH,

Mark

> Graap, Kenneth wrote:

I am already proactively "tuning" my system ...
What I'm trying to understand here though is whether or not there is an
objective way to monitor and analyze the utilization of RAM in order to
prove that there is an over commitment of this resource and that more is
actually needed. I want to spend time rationally analyzing how this
resource is being utilized precisely to avoid the option to:

"throw money at the problem" and just buy more real memory.

I'd like to know how the rest of you monitor the utilization of RAM.
For example, it is easy to monitor auxiliary storage utilization and
"prove" that storage is over committed as its utilization increases
above 80 or 90% ... How would you do something similar for RAM usage, or
can you?


Kenneth
Kenneth E. Graap