*BSD News Article 81705


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From: Andrew Szymkowiak <andrew.szymkowiak@gsfc.nasa.gov>
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: when does boot say "panic cannot mount root"
Date: Sun, 27 Oct 1996 16:34:29 -0500
Organization: NASA Goddard Space Flight Center -- Greenbelt, Maryland USA
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CC: aes

To answer my own question:

One of the times one cannot mount root is when the device
you are trying to mount is not the same as the root_device
that the root already mounted.  Several times in single-user
mode I have seen that error message when trying to do a mount.

My wd1 system would not boot when I would say

1:wd(0,a)/kernel 

to the boot prompt.  I thought this was the proper notation
for the BIOS "D" drive, since I knew that I had to say

2:sd(0,a)/kernel 

for the SCSI as BIOS "E".
I was being fooled since the "1:" form does start booting fine,
(rather than saying "no such device"),until it gets to the 
point where it "cannot mount root".

It turns out one should say

wd(1,a)/kernel

and things work fine now.  Some day I will have to try

1:wd(1,0)/kernel.

Thanks,
  Andy