1)kill all nobody process. use the following script for doing that.

for i in `ps auwx | grep -i nobody | awk {'print $2'}`; do kill -9 $i; done

2) if apache is not restarting after this. remove semaphore using the following script.

for i in `ipcs -s | grep nobody | awk '{print $2}'`; do ipcrm -s $i; done

3) restart apche.