How to stop running out of memory when working on your server

It’s a fairly simple thing to do, but I have seen a lot of people drive their servers really far into swap and kill performance due to an administrative action they are performing in the shell. Just open up another terminal on your server and run:

# watch free -m

This is pretty useful if you’ve not got much free memory to play with and you’re installing a gem, using irb or syncing portage or whatever and as long as you keep an eye on it you can terminate your process if it starts to eat too far into swap.