Problem was /etc has been burned too...  so the mknod command is off the table.


On Tue, Apr 25, 2017 at 10:08 AM, Larry McVoy <lm@mcvoy.com> wrote:
Whoever was the genuis that put mknod in /etc has my gratitude.
We had other working Masscomp boxen but after I screwed up that
badly nobody would let me near them until I fixed mine :)

And you have to share who it was, I admitted I did it, I think
it's just a thing many people do..... Once :)

On Tue, Apr 25, 2017 at 10:02:26AM -0400, Clem Cole wrote:
> 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
> >

--
---
Larry McVoy                  lm at mcvoy.com             http://www.mcvoy.com/lm