[emerg] (28)No space left on device: Couldn’t create accept lock
or
[crit] (28)No space left on device: mod_rewrite: could not create rewrite_log_lock Configuration Failed
Checking your disk shows that you have plenty of space. The problem is that apache didn’t shut down properly, and it’s left myriads of semaphore-arrays left, owned by my apache-user. Run:-

For CPanel :

ipcs -s | grep nobody
Removing these semaphores immediately should solve the problem and allow apache to start.
ipcs -s | grep nobody | perl -e ‘while (<STDIN>) { @a=split(/\s+/); print `ipcrm sem $a[1]`}’

For Plesk :

ipcs -s | grep apache
Removing these semaphores immediately should solve the problem and allow apache to start.
ipcs -s | grep apache | perl -e ‘while (<STDIN>) { @a=split(/\s+/); print `ipcrm sem $a[1]`}’