One of my apaches refused to start. It kept complaining about "[emerg] (28)No space left on device:Couldn't create accept lock".

df -h showed verything was ok. turned out that apache really is running out of semaphores.

Here's how to check:

 ipcs -s

Now, how do we remove the tied up semaphores? Use this:

 for semid in `ipcs -s | grep apache | cut -f2 -d" "`; do ipcrm -s $semid; done

Now, I can start my apache.

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