semget: No space left on device

This relates to semaphores on your system (you've run out).  Run the following to clear them out:

ipcs | grep apache | awk '{print $2}' > sem.txt
for i in `cat sem.txt`; do { ipcrm -s $i; }; done;

If this becomes a common occurance, then you may need to change your ipcs semaphore limits.
Set the following in your /etc/sysctl.conf:

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

and reboot your system to load in those values.

If that still doesn't help, then you could try using a cronjob to periodically check, and clear them out as needed.