topic Re: Memory Problem in Operating System - HP-UX

Memory Problem

karthiknarayan — Tue, 10 Oct 2006 02:00:53 GMT

I have a RP3440 machine with 16GB RAM.that runs 3 oracle databases and Tuxedo. The swap memory gets full to 100% suddenly.if i shutdown 2 oracle database it comes to 60%.But if i see all the process memory utilisation is is about 5Gb but in swapinfo it is 9GB utilised, why the memory is not freed up. please help

Re: Memory Problem

Frank de Vries — Tue, 10 Oct 2006 02:19:59 GMT

Some basic checks:
What is your exact Oracle version ?
Version of OS (uname -a)
What are the SGA size of each DB ?

Can you give a breakdown of ipcs -m
when all db are running and
compare that with ipcs -m when only one is running.

Check the resisent memory of your process
and how they grow by doing a full listing
of top processes and rerun every 10 seconds:

UNIX95= ps -e -o pcpu -o time -o ruser -o sz -opid -o args|grep -v %CPU| sort -nr|tail -n +2|head -n 20

Also if you have access to metalink, it
could be wise to log a call on the forum,
because you could be dealing with an Oracle bug with malloc, and then you will need a patch.

Re: Memory Problem

karthiknarayan — Tue, 10 Oct 2006 23:28:52 GMT

My system swapinfo says that the Mem used is 9224476,but when i see the mem usage of all the process is ts 1234827, why the swapinfo shows extra mem utilised, if there is a mem leak how to sort it out

Re: Memory Problem

A. Clay Stephenson — Tue, 10 Oct 2006 23:35:41 GMT

You are reading something into the "memory" line of swapinfo that is not there. The memory line refers to pseudoswap which isn't really swap and really isn't memory usage either. It's simply a kernel bookkeeping hack that allows the machine to count 75% of physical memory as though it were swap space for process reservation calculation. This allows a machine to actually be able to run with less actual swapspace than physical memory.

Re: Memory Problem

Frank de Vries — Mon, 06 Nov 2006 05:36:12 GMT

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Re: Memory Problem

Calandrello — Mon, 06 Nov 2006 06:11:12 GMT

Friend
he uses stm and he twirls one check in this memoria.

Re: Memory Problem

Jaime Bolanos Rojas. — Mon, 06 Nov 2006 07:12:48 GMT

Karthiknarayan,

Please keep in mind that applications like oracle will reserve a huge amount of memory for their use, and when that happens also a huge amount of swap will be reserved ( not used but reserved ).

The command I imagine you are using should be swapinfo -tam, if this is the case you should be concerned with the total line, than porcentange should never be close to a hundret porcent.

Also remember that for the same reason explained above, everytime that you reboot your machine, you will free up the memory, but as soon as the application starts it's going to reserved it again.

For more information on what is using your memory refer to this manual:

ftp://eh:spear9@hprc.external.hp.com/memory.htm

Regards,

Jaime.