Recently we encountered some strange issues with httpd on some of our CentOS 7 machines during my current project.

Through our pipeline we restart httpd several times which sometimes leads to this error:

Apache: [error] (28)No space left on device

After some research we found out the semaphores were all being used blocking httpd daemon to restart.

The list of semaphores can be fetched by issuing

# ipcs -st

------ Semaphore Operation/Change Times --------
semid    owner      last-op                    last-changed
753664   apache      Not set                    Mon Feb 17 20:20:47 2020
786433   apache      Not set                    Mon Feb 17 20:20:47 2020
720898 …

Cloudstack, an item I had on my todo list with some lower priority against daily maintenance of our server park. But since attending David Nalley's talk on LinuxCon I shifted it up some places. Although I expected a real hands on session the talk he gave about a cloudstack environment for development was really intriguing and matched completely with what I had in mind.

Being fully convinced it fits in my idea of a fully automated development environment which meets to all the needs of developers to start writing code real quickly on machines similar to the production environment.

At …