Segmentation fault - or Segmentation fault (core dump).
When you experience this - which can be thrown by any service, software og deamon on your Linux host, just restart the server to get back to working order. However, this most likely occurs due to exchausted resources on the host, so you should be aware of a few things, albeit exchausted resources is not always the only possible cullprit.
If this happens frequently you need to investigate what eats up your resources or add more to your server.
If this has happened only once, then keep an eye out for any new occurances and adjust a few things to opimize resource consuption.
Be warned that this faulty state is not always triggered by eating up all the resouces of a host system, so try with a restart first and if that does not help, you need to monitor resource consumption (top or htop is good) or look in log files for the services or component failing.
I have had this state once in 10 years, and a restart did the trick for me.
Yeah. That is also what I write. For me, this has happened once. It was due to cron jobs and backup routines running at the same time as I also ran AV scan. As I write: If this happens once or twice in years between, it is probably not worth the effort to try and fix. However if happening more frequently, you need to identify what eats your resources and adjust your settings. The restart is needed in both occasions anyway.