Re: dd: /dev/rsd1c: device not configured

On Tue, Nov 30, 2021 at 02:36:22PM +0100, Luca Ferrari wrote:
> Hi,
> I'm trying to install 7.0 in a virtual box machine using full disk
> encryption, following
> <https://www.openbsd.org/faq/faq14.html#softraid>. I've done it on
> real hardware without a problem, but I'm not understanding the error
> in the virtual box machine. In particular, I cannot copy random data
> on the disk before doing the effective encryption.
> This is what I do, after entering the shell at the very first prompt:
>
>
> # sysctl hw.disknames
> hw.disknames=wd0:,cd0:,rd0:7c72fe60b4e2338d
>
> # ls /dev/rsd*c
> /dev/rsd0c
>
> Uhm, why is sd0 there and does not appear in the hw.disknames?
> However, I tried to configure the sd1 device:
>
> # cd /dev
> # sh MAKEDEV sd1
> # dd if=/dev/urandom of=/dev/rsd1c bs=1m
> dd: /dev/rsd1c: device not configured
>
> # ls /dev/rsd1c
> /dev/rsd1c
>
> What am I missing here?

You've successfully created a set of device special files in /dev/ for
sd1, I.E. files that have a major device number of 4, and corresponding
minor numbers for each partition.

But since there is no sd1 device present in your, (virtual), machine,
you get the device not configured error. You're trying to talk to a
device that does not exist.

If your main disk is attaching as wd0, you will need to specify
of=/dev/rwd0c in the dd command to write scratch data over it.

Assuming you don't have any sd devices, when you create the softraid
volume, it will appear as sd0.