No space left on device: AH00023: Couldn’t create the rewrite-map mutex
AH00020: Configuration Failed, exiting
ipcs -s | tail -n +4 | head -n -1 | tr -s ' ' | cut -d' ' -f3 | sort | uniq -c | sort -nr
123 apache
1 root
ipcs -s | tail -n +4 | head -n -1 | tr -s ' ' | cut -d' ' -f2,3 | while read -r id owner; do [[ $owner == "apache" ]] && ipcrm -s "$id"; done
service httpd start
Also you can try reboot server.