Earlier today, we faced an issue when the Apache (MPM, installed over CentOs on AWS Cloud) server went down and we were unable to restart the same. The error which we got on the error log was:
No space left on device: AH00023: Couldn't create the ssl-cache mutex
We looked up for available help on the internet and we got this command from this answer:
ipcrm -a
While this worked for us, we are not really sure how to avert such issues in the future. Hence, here are a few questions the answers to which will be very helpful for us to take the next steps in maintaining higher uptime for our web application.
- When does it require to clean up the semaphores?
- If semaphores are running short on count / space, what should be the length / space we should allocate ?
- What causes such types of errors on Apache?
- Is there some Apache configuration we need to tweak to avoid getting in such situations?
