Linux VM: Overcommit Memory and Ratio

[Anthony M. Rasat]

Heya guys,

I had a OOM (Out Of Memory) situation. This machine have 512 MB RAM and 1 GB swap running Apache MySQL PHP. Something went wrong in PHP (which I'm not gonna discuss) and MySQL ended up wanted memory more than system ever owned.

Now, to avoid that incident in future, I readjusted /proc/sys/vm/overcommit_memory to 2 (default 0) and /proc/sys/vm/overcommit_ratio to 50 (default 50 too).

My question is what side effect will showed up? Will MySQL start to slowing down? Will Apache begin to fail? I know more RAM is better idea but what if PHP gone berserk again? Will it better if OOM killer kept loose otherwise? Thanks for your insights.

-- 

Regards,

Anthony M. Rasat
Manager - Technical, Network and Support Division
PT. Jawa Pos National Network
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