When dealing with mem-leaks in my mod_perl-apps I ran into a curious apache-problem. After a while apache could not be started but failed with strange errors like:
[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
or
[Wed Dec 07 00:00:09 2005] [error] (28)No space left on device: Cannot create SSLMutex
There was definitely enough space on the device where the locks are stored (default /usr/local/apache2/logs/). I tried to explicetely different Lockfiles using the LockFile-directive but this did not help. I also tried a non-default AcceptMutex (flock) which then solved the acceptlock-issue and ended in the rewrite_log_lock-issue.
Only reboot of the system helped out of my crisis.
Solution: There were myriads of semaphore-arrays left, owned by my apache-user.ipcs -s | grep apache
Removing this semaphores immediately solved the problem.ipcs -s | grep apache | perl -e 'while (<STDIN>) { @a=split(/\s+/); print `ipcrm sem $a[1]`}'