Subject: Re: Install NetBSD over the top of Linux
To: None <current-users@NetBSD.ORG>
From: Laine Stump <>
List: current-users
Date: 06/17/1996 02:02:21 (Carsten Hammer) wrote:

>> >1. Major and minor device numbers dont conform to any standard.
>> >   (is there any?)

>What i mean is that i think it would be useful to have the harddisks on
>NetBSD-Amiga have the same Major and minor numbers as NetBSD-i386,
>I dont mind to change the NetBSD-Amiga device numbers to i386 style..
>Of course it is difficult to do it with all devices as same are uniq on
>some platforms but it should be possible to find a way to get NetBSD-Amiga 
>boot on a NetBSD-Mac Harddisk after replacing /netbsd by the NetBSD-Amiga 
>version. As i understand it it is necceassary for this to match the
>device numbers to the same hardware devices on the different platforms.

The problem isn't the device numbers not matching, the problem is that
during the boot process there is much more being executed than just the
boot loader and the kernel image. There is so much involved here that
having matching device numbers would be less than a dent in the fender
of the truck.

>And at least the major number distribution seems to be completely
>arbitrary on the different NetBSD ports and Unixes in genereal.

Standardization is (almost) always a good thing, but I don't see that it
will buy you anything worthwhile in this case.

>> - NetBSD doesn't know how to run Linux binaries (you might be able to get
>>   by with Linux binary emulation, but I'm sure lots of things won't work).

>I was under the impression that NetBSD's Linux emulation has improved very
>well. What exactly it the problem? 
>Would it be possible to replace these parts and make it then work?

The Linux binary emulation is intended for running *application*
programs, not system utilities. Any linux executable that has its grimy
little paws down into the kernel data structures *will not work*. This
includes a great percentage of programs run at boot time, as well as
many run after boottime. If you think this is a deficiency, then think
again - why should the NetBSD developers work their collective butts off
to allow proper execution of a bunch of Linux system utilities that are
included in NetBSD anyway?

>no, I mean to share the most important major,minor numbers under all free unixes.
>The reason is to boot into a different operating system with minimal work.

Again, the only thing this would affect is the contents of /dev, nothing
else. Besides, if you look at most BSD-style Unixes, you'll find that
the major device numbers of any particular device will vary from
*installation to installation*, not just from one flavor to another;
this is because the major number of a device is derived from its
position in a table of all devices on the system, and the configuration
process could put the devices in any order it liked (which is why those
numbers are, as you noticed, "arbitrary").

Taking it a step further, OSes like Solaris (and at least one other I'm
not at liberty to discuss right now) reserve the right to change the
major number of a given device *at each and every boot* as they see fit.
Relying on a device number being any particular value has always been
discouraged, that is why the /dev directory exists on BSD systems. Now
you're suggesting taking something that was designed for flexibility and
making it more rigid. I'll pass.

>Unfortunatly this means to introduce a non transparent way to 
>interpret msdos files as special files. How does linux do this? 
>I heard it is able to boot from msdos fs. 
>NetBSD doesnt boot at all if there are no special files. It doesnt even 
>give a errormessage.

The MSDOS file system is so brain-damaged and low performance that I
would consider it a waste of time to put stuff into NetBSD to allow
booting and running from a DOS partition.

>> >Is there a way to boot my box on a NFS mounted NetBSD-rootfs and
>> >to install then via NFS?(security considerations are no
>> >big problem for me, at least as long only this machine is affected)
>> I think you might be able to do an NFS-mount off of one of the install
>> floppies ... but if you can do that, why not just ftp the installation
>> sets?

>perhaps anybody out there knows something about this more exact?!
>I cant see what ftping helps me if i dont have the space to hold the
>NetBSD distribution on the msdos partition. 

1) You don't need to ftp the installation sets onto the msdos partition.
The installation boot disks contain networking in the kernel, and have
an ftp client. Boot from the installation diskettes, run Install, then
ftp all the files *onto the NetBSD parition*, then do all the Extracts
(erasing as you go if you need).

2) I thought I had CC'ed a private mail to you about this, but possibly
not. I routinely install NetBSD via NFS. I have put all the NetBSD
distribution onto a directory on an NFS server which can be mounted from
a particular "spare" address. When I want to install NetBSD, I just boot
from the install floppies, go through the Install script (that is
automatically run), then do:

    ifconfig ed2 blah blah     - configure my ethernet card
    mount_nfs   x.x.x.x:/dir /mnt2 - x.x.x.x is the IP address of the
				     server, dir is the volume containing
				     the NetBSD distribution
    ./extractall		- a short script which does the same thing
				  as the standard one-by-one install thingy
    Configure			- setup /etc
    <remove the floppy>

Your usage will vary slightly, of course, since you will have a
differently named ethernet, etc. the extractall script is short and
sweet, directly derived from Extract. But if you want a copy I'll be
glad to email it to you.