[TUHS] was turmoil, moving to rm -rf /

Clem Cole clemc at ccc.com
Wed Apr 26 00:02:26 AEST 2017


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 at 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
>
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