Larry,

I had to laugh when I read that because what you don't know is it was part of my old Unix wizards test which was left over from a the day when one of our hackers (whom I think you would later get to know so I'll not name him) accidentally typed: rm -rf . as root from his / on his workstation.

Because /bin/rmdir had been lost, he started getting errors when rmdir was forked. So he hit ^C, but he had already lost: /bin, /dev, /etc, /lib, most of /usr. He was a developer in the networking group so he was working on network code which we could not trust would not panic (in fact we disconnected the node from the ethernet immediately just in case). But we did have pretty much everything in /usr/bin/[s-z]* -- that is we think it was deleting files in /usr/bin when he stopped it.

We obviously had another working Masscomp box just like it. And of course the shell was working on the machine that was in trouble. We recovered the system as it was. Hint the key item is you have to start by putting /dev back together and the solution to that problem has had been discussed on this list.

Clem

On Mon, Apr 24, 2017 at 7:59 PM, Larry McVoy <lm@mcvoy.com> wrote:

This is gonna seem like I'm tooting my own horn, and I am a little, but
here's an rm -rf / story.

Clem will be amused because I was a junior or senior in college and a sys
admin for a Masscomp with a 40MB disk with 20 users. And I did some version
of rm -rf /, realized part way through that I screwed up, and killed it.
But /bin and /dev were gone so putting things back together was hard.

But I did it and wrote up this little note for the people who came after
me, if I was stupid enough to do this someone else would, was my thinking.
You can get a sense of how scared I was in it if you read it carefully.
It was a very long night.

For an undergrad, I think it's not bad? Maybe? I dunno, I look at how
much I needed to have understood to get the system back up, that's a lot
of reading, playing, experience. Love that Geophysics department, they
pushed me.

And it was during my (brief) foray into the *roff -me macros (I went
-ms and never looked back). Roff source on request to anyone who is
twisted enough to want it.

http://mcvoy.com/lm/masscomp-restore.pdf

Complete with all the typos.

--lm