Swap is not being used

[Joe Kanakaraj]

Hi Guys I have a probelm on a dual processor rp7410 with regards to swap.

The machine is not utilizing swap at all and hangs the entire sytem. We run oracle on it with multiple instances. My swapinfo out put is given below:-

Kb Kb Kb PCT START/ Kb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 4194304 0 4194304 0% 0 - 1 /dev/vg00/lvol2
dev 4096000 0 4096000 0% 0 - 0 /dev/vg00/swap2
reserve - 8290304 -8290304
memory 6469772 6149456 320316 100%

Memory usage is 100%. WHen I check for swapping with a swapon -a I get a message that the swap space has already been enabled. my maxswapchuncks parameters is 16384. I tried a reboot but the bottleneck comes back up.

Any ideas as to what is going on????

Joe

[Deepak Kulkarni]

Hi Joe,

you have to set swapmem_on=1 in kernel tunable parameters.

Cheers
Deepak Kulkarni

[Jdamian]

Your swap is not the problem. Your problem is the memory utilization. I think there is not enough memory.

Run the following commands:

ipcs -mob # for displaying shared memory segments

kmtune -q dbc_max_pct # for showing upper limit of memory use by buffer-cache

/usr/contrib/Q4/bin/kmeminfo # for reporting memory utilization

[Joe Kanakaraj]

swapmem_on is set to one

Joe

[Joe Kanakaraj]

I have a physical memory of 8Gig...even if my physical memory is fully utilized I should be able to swap..right????...the probelm is swapping in not taking place..

Joe

[Jdamian]

Ok

excuse me for trying to help you.

bye

[Joseph Loo]

hi joe,

listen to J. Damian.

the info he requested is valid in order for us to help u.

since u r running Oracle (and multiple instances!), we would need to ascertain how big a SGA u have created which may have cause this full memory.

regards.

[Joe Kanakaraj]

Damian

My apologies.I did not mean that the way it sounded. Its a production box and I don't know what I am doing. Well a reboot again seemed to help and now I am down to 13% of memory used.

I will post the details once the problem starts coming again since we cannot get the exact details right now, since the server is functioning normally.

I am guessing the defunct processes casued by oracle was hogging up the memory.

Once again my apologies.

Joe