On 2019-08-17 08:42, Jonathan Billings wrote: > On Aug 17, 2019, at 9:25 AM, Valeri Galtsev <galtsev at kicp.uchicago.edu> wrote: >> I like this one. Long-long ago it was one of the “tricky” questions at the UNIX admin test (exam). Basically, no matter how devastating that may sound, the command only will remove what is (alphabetically it was that time) before /dev/[root_device]. Once the device root filesystem lives on is removed from /dev, no further damage is done. So, you will be able to mount drive on another machine and get your /etc, /home, /var, /usr/local intact ;-) Asking that question other people gave me (an them usually) a lot of fun. > > > I’m not sure what UNIX systems where that’d actually happen, but on Linux systems, removing the device in /dev/ would not deter rm from being able to delete everything else on the mounted filesystems. > > Certainly if you were using some sort of automount system, and the filesystems hadn’t unmounted, it would be fine. > Thanks, everybody, for confirming that on Linux rm -rf / does lead to devastating result. Just for fun I tried the same on FreeBSD (12.0 RELEASE - which is latest release): root at point:/home/valeri # cd root at point:~ # whoami root root at point:~ # rm -rf / rm: "/" may not be removed Somebody is really clever in this World ;-) Well, FreeBSD folks made my day (again!). Note, that that I did on my live workstation (yes, I did test it on throw-away system first ;-) - so I can copy and paste what I got to this email. Valeri > -- > Jonathan Billings <billings at negate.org> > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos > -- ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++