OOM on linux

linux_@dmin · 12-29-2008, 05:54 AM

Dear All,

I have enabled few settings to check the OOM condition. But i dont know how to manually crash the server due to OOM.

Thanks & Regards

Linux_@dmin

"if you are living on edge, you are taking too much space"

syg00 · 12-29-2008, 05:59 AM

Oracle ???
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Sorry, couldn't resist ...

rweaver · 12-29-2008, 12:12 PM

Quote:

Originally Posted by linux_@dmin

Dear All,

I have enabled few settings to check the OOM condition. But i dont know how to manually crash the server due to OOM.

Thanks & Regards

Linux_@dmin

"if you are living on edge, you are taking too much space"

I assume "OOM" means "Out of Memory", there are several possible scenarios the most simplistic being a perl script or small c program that calls itself a given number of times and allocates a sizable chunk of memory and sleeps to hold onto it.

Basically a controlled memory intensive fork bomb (or uncontrolled if you're feeling lazy and the server can crash without a problem.)

What are you working on? Disaster recovery? Load testing?

linux_@dmin · 12-30-2008, 12:02 AM

Hi,

Can you please send me any such script ?
I have added following parameter in /etc/init.d/sshd such a way that ssh will be available in case of OOM.

startproc -t 5 -f -p $SSHD_PIDFILE $SSHD_BIN $SSHD_OPTS -o "PidFile=$SSHD_PIDFILE"
echo -17 > /proc/$(cat $SSHD_PIDFILE)/oom_adj

rweaver · 12-30-2008, 07:54 AM

Quote:

Originally Posted by linux_@dmin

Hi,

Can you please send me any such script ?
I have added following parameter in /etc/init.d/sshd such a way that ssh will be available in case of OOM.

startproc -t 5 -f -p $SSHD_PIDFILE $SSHD_BIN $SSHD_OPTS -o "PidFile=$SSHD_PIDFILE"
echo -17 > /proc/$(cat $SSHD_PIDFILE)/oom_adj

I would rather not as it can be easily used for nefarious purposes, the script itself is trivial and a google search for "fork bomb" should provide you all the direction you need.