Hi,
Can some body describe me how my OS memory usage goses beyond my set maximum JVM

case:
Websphere 6.1
min JVM -512
Max VVM-2048
garbage colletion enable
linux RH4 64
OS mem cunsumtion 3.5 GB out of 4 GB

I am telling it grows out of max is because ASAP I restart JVM OS memory clears

[quote author=144332197 post=518522019]Hi,
Can some body describe me how my OS memory usage goses beyond my set maximum JVM

case:
Websphere 6.1
min JVM -512
Max VVM-2048
garbage colletion enable
linux RH4 64
OS mem cunsumtion 3.5 GB out of 4 GB

I am telling it grows out of max is because ASAP I restart JVM OS memory clears[/quote]



I think by "min JVM -512 / Max VVM-2048" you mean the HEAP Size configured for your websphere application server.
The process memory (which you see on OS level) is bigger than the HEAP Size configured, because HEAP is only one part of process memory. I think there is a good documentation in infocenter, but I can't find it atm.
However at European WebSphere Technical Conference 2010 I attended a presentation on Java Performance Tuning in which the speaker told us to assume "process memory = HEAP * 1,5" or "process memory = HEAP * 2" as a rule of thumb.

If OS memory is a problem, either add memory to your linux server or decrease HEAP Size.
Are you using 32bit oder 64bit WebSphere Application Server V6.1? On  WAS6.1's java, 64bit has some overhead in terms of memory consumption due to 64bit object references. Starting with WAS7, 64bit java supports compressed references with which this overhead is nearly nullified. 

oh so I was Wrong informed ,

now It makes sense , can you please help me findout what other process other then JVM are included in OS java process

you can see each server of websphere running as one java process. for example: a server, a nodeagent, a dmgr will have one java process for each. you can use the "ps -ef|grep java"  command to see all the process. 

To see the details of the memory and cpu usage of a process, use "top -p PID" command. Note that it details VIRTual memory, RESident memory and SHRed meory as well. %mem is the percentage of physical memory that process is using.

For a detailed listing for memory usage by a process, you can check the file under :
/proc/PID/smaps.

PID is the process ID 

thanks for describing ,
but how can I investigate if problem in in my JVM or in OS

[quote author=144332197 post=518555395]thanks for describing ,
but how can I investigate if problem in in my JVM or in OS


[/quote]
What problem? That your available memory (or too much of it) is being used?

You may want to look at the ISA toll it has a memory analyzer that has help me in the past with a runaway application.

www-01.ibm.com/software/support/isa/

You can also enable Performance Monitoring Infrastructure (PMI) within WebSphere. But I caution you on doing so in production.

publib.boulder.ibm.com/infocenter/wasinf...