Subject: Re: (LONG) Re: pmax installation
To: None <email@example.com>
From: Andy Sparrow <firstname.lastname@example.org>
Date: 01/07/1997 14:24:49
> I have a document that describes how to boot a 5k from another
> partition, but I've never tried it myself. I had a 2100 for NetBSD at
> the time and have used it for subsequent installs, so I never got to try
> this out. Hope it helps/works!
I wuz wrong...
I went home last night and actually tried out the suggestions I
made to Olivier, and then made a point of sending him an email
before packing up for the night telling him that what I
suggested wouldn't work, the kernel panics when you try to
overwrite the root partition...
I didn't Cc the list because I was on a dial-up link and I've
forgotten how to drive those now.. :)
Actually, I found that the following command:
(where I had a miniroot on partition 'd' and nothing other than
a clean filesystem in 'a')
actually booted the kernel, and everything looked good until it
prompted for the root partition (GENERIC option), and then it
all went horribly wrong. But the kernel did boot, and found all
the devices and stuff, much to my surprise.
I think my PROM version(s) are 5.7 or something like that, but
I can check that out (I mean to experiment with the diskless boot
stuff and feedback the results, simply because I have a pile of
old hardware, all with slightly different PROM versions, it seems).
(Attached is the mail I sent to Olivier last night).
Oops, some good news and some bad news:
1) I was wrong, you _can_ specify the partition to boot
on pmax, as in:
And this works fine on my machine, right up until it
prompts for the root partition (my kernel still has
the GENERIC option).
And then it dies horribly (because the GENERIC kernel
has a default root partition of 'a' built into it, and
I blew this partition away to make sure it wasn't getting
However, this command should get you far enuogh to see the
messages written by the kernel when booting.
The fact you get errors seems to indicate that there's
something else wrong.
Did you 'dd' the miniroot to the 'd' partition?
Did you use the skip/seek options to 'dd' for this
'dd' too? This won't work, it's only the 'dd' to the'a'
partition that needs that (to miss the label written
ii) The list of operations I outlined in the previous mail
won't work. (it's been a long time since I saw a 'text
file busy' message).
The kernel will panic if you attempt to overwrite the
root filesystem in the way I describe, although it
gets far enough to make you think it'll work.. :)
It actually happily 'newfs's the root partition, it
only seems to realise what's happened when you try
to 'tar' the new stuff onto it...
iii) So, you can't boot the miniroot from any other partition
than the first ('a') partition on a disk, and you can't
overwrite the root partition.
There really does seem to be No Other Way than to use
a.n.other disk as the target for the new 'root' and 'usr'
filesystem(s), and then boot from those.
If you really have only the two disks, then your options
would seem to be limited to:
a) Overwriting the other one
b) experimenting with the diskless boot
support and seeing if you can get that
working well enough to install the
full distribution on your single disk
c) Getting an archive that consists of a full
filesystem that you can 'dd' onto your
Of course, if the situation is that you don't dare (or can't)
overwrite the Ultrix disk and you don't have access to another
machine (or can't make the diskless support work with your PROMS,
which may be a possibilty), then the last is really your only
Adding another "scratch" disk would seem to be the easiest.
So, sorry for misleading you there. If you get stuck, let me know
if there's anything I can do to help, like sticking a suitable
filesystem or two on a QIC, TK50 or an FTP site?
(I have spare disks, so it's not a problem to build some
filesystems, I'd just need to know what sizes you need 'em).