[CentOS] Anyway to ensure SSH availability?

> Although it would really be interesting to me to see scheduler settings that would indeed allow something of a 'privileged' ssh or an OOB console that would be responsive even under a punishing load with lots of swapping, which is what the OP originally asked about.

I should add, we have OOB management facilities available but even the console login was unresponsive. The one SSH login that was logged in at the time the trouble started wasn't capable of terminating any of the problematic processses or issuing a graceful reboot sequence. Pressing the power button and/or Ctrl+Alt+Delete would return "Shutdown: already in progress" (which I eventually gave up waiting for).

Cheers

Steve