Overview

With the release of Linux 7.2. came a little change which affected every application meant to run on it. That is the change of the default behaviour of what happens when the user logout. Up to now it was that the system won't kill your Inter Process Communication (IPC), which is controlled by the following configuration file: “/etc/systemd/logind.conf”

Default settings:

logind Config File

Well, that leads to little problems for Oracle, let see what:

Consequerneces for Oracle

Oracle highly relies on semaphores, as every other application, semaphores are used to create locks (latches, enqueues, mutexes, etc…) So what happens when we remove the semaphores after the DBA logs out ?

Well this happens:

Oracle Crash

In a nutshell, oracle crashes, because it cannot open its semaphores anymore. You can of course investigate the stack:

Investigate the Stack

From the stack, you can see that it failed because it allocate the memory to start.