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Date: Tue, 21 Oct 1997 11:45:18 +0200
From: Nadav Eiron <nadav@barcode.co.il>
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To: JBradley@ucsd.edu
CC: FREEBSD-QUESTIONS@FreeBSD.ORG
Subject: Re: panic: cannot mount root
References: <199710210651.XAA10415@sdcc14.ucsd.edu>
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JBradley@ucsd.edu wrote:
> 
> To whomever wants to help:
> 
> After a minimal install of BSD, it fails to boot correctly.  Here is the
> setup.
> 
> 2 disk system
>    1st disk is pure DOS and booteasy
>    2nd has 32M DOS partition at front and FreeBSD slice on remainder.
> Disk 1 shows up as wd0
> Disk 2 shows up as wd2 (that's wd2, NOT wd1).
> 48 M ram. (I saw the similar problem in errata that involver 48M machines
> and failure to mount fd0 as root during install.  I tried the solution
> given: I went into config and set "iosize npx0 32768" but it didn't work.)
> 
> When the kernel loads, all devices are probed correctly.  When system
> attempts "changing root device to wd1a," the system panics with "panic:
> cannot mount root" and restarts.  The odd thing is that, during setup, the
> root "/" partition of the FreeBSD slice showed wd2s2a, and the drives were
> wd0 and wd2.  It seems like the kernel is looking to wd1 for the root.  How
> can I change this to get it to boot properly?
> 
> Thanks,
> Justin Bradley

Give the line 1:wd(2,a)/kernel at the Boot: prompt. You can use
/boot.config to make that change permanent (assuming you have a recent
enough version, which you do not specify).

Nadav