When you've rm'ed your whole filesystem, what does rm, the actual executable, do then? Self-destruct? Commit suicide? Go round in ever decreasing circles and disappear up its own backside?

Sorry, probably not anything quite so dramatic......

I'd assume that rm was running from RAM---it would erase everything and then stop.

More generally, what happens when you run any program (which is this context means any callable code--utility, application, etc.)? My assumption: the code is loaded into RAM, and control is passed to it. From that point forward, it does not care what is on the disk---until it needs something. So---in the case of rm (or any number of simple utilities)---it just runs until it's done.

This would be easy to test----but I'm not going to..

I suppose I could install a distro in VirtualBox and try it sometime.

Thanks, rich_c. I was thinking it might be best to drop to a CLI runlevel, shut down X first. Interesting experiment.

you could always copy your root filesystem files to a sub directory then chroot to make it the root, rm it, then after a force reboot with the power button it will be back to normal.

Hmm, it wipes the inode-tables so every reference to every file is delete. So if you're lucky and pull the power cord, you can recreate > 90% of the deleted files as the data is untouched.
I want to try this out in a controlled environment as an experiment some time. Possible in the winter if I don't forget it :P