Question: If you are root, and you issue 

```
rm -rf / 

```

Then how far can the command go? Can you recover data from this kind of an action? Even after the binaries are gone, would the running processes still be active? What would it take to make the same physical machine boot again? What files would you need to restore to make this happen?

I could try this on a VM and see, but I want to know the rationale behind what to expect if I do this.

Answer: 
I just tried with Ubuntu 16 and vmware workstation and with the no-preserve-root option it erased the entire disk of my running linux system. after that was finished the whole vmware workstation app became unusably instable and even powering off or resetting the virtual machine from the application was impossible.
Killing the vmx was refused only a host reboot worked after that!
One can't simply destroy his/her system by issuing `rm -rf /` as root. Initially, the command will be issued under fail-safe mode, which will restrict the usage of `rm` on `/` but even with `--no-preserve-root` as an argument, the running system will not permit the removal of running processes from the disk; however, the rest of the programs and files will be removed, leaving an unusable system with (almost) no programs to run! Please check the screenshots tarred here, the command was issued in Arch Linux in Virtual Box: <http://bit.ly/q9CsA4>