Turning it off and on again

My IT experience reaches far back into last century’s 80ies, but no matter how deep I delve into the various subjects, there’s always something new to learn, every day. Like this tiny bit of information that I want to share with you today: I was updating RPMs on a live server, in preparation for a scheduled maintenance later that week. Usually I see that program files and configurations get updated during the installation of the patches, but the services remain active (and will run off the original versions of the files). It definitely isn’t best style to pre-update this way, but may help you to save tremendous amounts of time, especially if you have to update quite a number of systems simultaneously. Like in my case, a larger set of virtual machines, running in a Pacemaker cluster of Xen servers… Those Xen servers, of course, were in for updates as well. But during installation of the openais update, I noticed that the post-installation script tried to restart that service, with almost fatal consequences to the clustered resources on that node! Continue reading →