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From: jsdy@hadron.UUCP (Joseph S. D. Yao)
Newsgroups: net.unix-wizards
Subject: Re: Being `well and truly up the creek'
Message-ID: <79@hadron.UUCP>
Date: Sat, 16-Nov-85 17:31:20 EST
Article-I.D.: hadron.79
Posted: Sat Nov 16 17:31:20 1985
Date-Received: Mon, 18-Nov-85 07:59:25 EST
References: <2968@sun.uucp> <2200@umcp-cs.UUCP>
Reply-To: jsdy@hadron.UUCP (Joseph S. D. Yao)
Distribution: net
Organization: Hadron, Inc., Fairfax, VA
Lines: 23

In article <2200@umcp-cs.UUCP> chris@umcp-cs.UUCP (Chris Torek) writes:
>One of the most, er, `interesting' things that can happen to a root
>file system is to lose /dev (have it turn into an ordinary file or
>soemthing).  If you have lost /dev, *and nothing else*, it would
>seem perfectly reasonable that /etc/init could come up single user
>by creating a new console device.  Of course, it will not, and one
>is forced to recover with standalone programs or a 4.2-style minifs.

The  r e a s o n  it will not, is that to do so means changing the
root file system.  Quite possibly, this will destroy some vital data
that would have let you fix the file system easily enough.

I had a disk drive go bad once and write one bad block in the root
file system.  It happened to be the one containing the inodes for
/bin, /etc, /dev, ... .  After the drive was repaired, I sat down
with a volcopy'd backup and copied the one block back.  Presto, a
perfect file system.  IF I HAD CREATED /#console, I NEVER COULD HAVE.

The hard part of the above, of course, was tracing the symptoms back
to finding that there was one bad block......
-- 

	Joe Yao		hadron!jsdy@seismo.{CSS.GOV,ARPA,UUCP}