Hi All.

I have access to a server running Linux Redhat. I need to run some very memory intensive processes.

My question is this:

What would happen to the server if I ran a process that used more and more memory until it got to 100% (shown in %mem when running 'ps au' command). Would it crash the server, or would it somehow know who to handle it (e.g. simply terminated the process)? I'd like to ask rather than try it out and crashing it.

Thanks.

It would never get to 100% anyway.

You ought to have a decent amount of swap space.

If you have too little swap space, some process will get killed when too much mem+swap is used, but not necessarily the process using too much. The results might be as bad as crashing the whole server.

If you have enough swap space, a process trying to use "too much" memory will still get significantly less than 100% in %mem (which is ram and doesn't count swap). It and other processes will swap more, which depending on access pattern might drastically slow them down.

If you have enough swap space, setting the CPU priority low on the process that tries to use "too much" memory will tend to make it be the one that does more swapping and thus gets more of the impact of its own memory use. But that is an indirect effect. It is hard to make sure other processes won't slow to a crawl due to the excess swapping.