Subject: Re: "panic: cannot mount root" with -current kernel and SCSI disk
To: Joachim Koenig <>
From: Alistair G. Crooks <>
List: current-users
Date: 12/07/1994 06:27:01
> I build a new kernel from -current last weekend.
> It runs without problems here at work on a i486 with Adaptec 1542B and a
> SCSI-1 Maxtor LXT213S HD.
> When I boot the same kernel at home on my i486 with Adaptec 1542B and a
> SCSI-2 IBM 0662 HD, the kernel panics right after device probing when it
> tries to mount sd0a as root (I also have a Toshiba 3501B CDROM connected).
> The disk parameters are correctly inquired from the disk during autoconf,
> but when the kernel tries to mount the root, another inquiry takes place,
> which returns all 0s for the parameters (heads, cyls, ..).
> The kernel then panics and returns to the debugger, but the screen display
> is munged. The debugger displays a few characters in one row, then a few
> rows further, the next few characters are displayed a.s.o, so that
> debugging is areal nightmare (this happens with different console drivers).
> When I make a bootable floppy with the new kernel and boot from that, all
> works fine, I can even mount sd0a without any problem.
> An 1.0beta kernel runs just fine without any problems.
> Has anybody else had similar problems? Otherwise I'd like to dig deeper
> into the problem.

I had the same problem, but only on kernels with generic as the swap
device - try changing "generic" to the actual devices. It worked for me.
e.g. in kernel config file:

config netbsd swap generic
# this gives me a page fault when it tries to access swap space on booting

config netbsd root on wd0 swap on wd0
# this works fine

Or have a look at the TRINITY config file.

Alistair G. Crooks (			   +44 125 234 6377
Amdahl European HQ, Dogmersfield Park, Hartley Wintney, Hants RG27 8TE, UK.