Within the Apache error logs, this message was appearing over and over:

[emerg] (28)No space left on device: Couldn’t create accept lock

1. Check the disk space

2. Review filesystem quotas

3. Clear out the active semaphores

# ipcs -s

If you see a list of semaphores, Apache has not cleaned up after itself, and some semaphores are stuck. Clear them out with this command:

# for i in `ipcs -s | awk ‘/httpd/ {print $2}’`; do (ipcrm -s $i); done

Now, in almost all cases, Apache should start properly. If it doesn’t, you may just be completely out of available semaphores. You may want to increase your available semaphores, and you’ll need to tickle your kernel to do so. Add this to /etc/sysctl.conf:

kernel.msgmni = 1024
kernel.sem = 250 256000 32 1024

And then run sysctl -p to pick up the new changes.

• apache