Re: re-transmission: Re: Prepping to install

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Mon, 15 Jun 2015 17:35:47 -0453
    From:        "William A. Mahaffey III" <wam%hiwaay.net@localhost>
    Message-ID:  <557F51CC.7090206%hiwaay.net@localhost>

  | > Could you amplify on this point a bit ? How does it steal root ?

The raidframe code, when it autoconfigures a raid array marked as being
the root, changes whatever would have been picked as root, replacing it
with the raid (raidNa - if you're using wedges rather than a disklabel,
inside the raid device, you need a wedge labelled as "raidNa" for whatever
is the appropriate "N").   When everything is working, it is great, as it
makes the root be where you want it to be regardless of how device naming
changes, but when it doesn't ...

  | *C'mon* !!!! How about a clue here ?

The suggestion that was made earlier (boot -a) would be the normal way,
then you get to override the root setting, very late in the boot process.

But as (for whatever reason) your keyboard isn't working at the point
where you would do that, it gets hard...

  | how do I recover ? Pull the 2 offending 
  | drives & dd a bunch of zeroes to the 1st few KB ?

That is more or less what you will need to do, but you will need something
other than NetBSD to do it, as if either of the drives is connected at
boot (before it is fixed) it will be enough for that to steal root, then
as it doesn't have enough of /dev (which I think the problem was) to actually
boot, you're stuffed...

So you might need to use something other than NetBSD - either that, or
stick the drives in a USB enclosure, and plug them in after NetBSD is
booted.   If you can do that, you could just config the raid, and then
turn off the autoconfigure flag (or the root flag), which would leave
everything else intact.

If you do it using some other OS (a live boot from DVD or USB of FreeBSD
or linux should do, without actually installing) I'd zap at least several MB
to make sure that you get the raidframe headers.

Before you turn on autoconfig root next time, you should set up the
raidframe, get everything on it that you think should be needed, then
chroot into it, and test that everything that matters seems to work
(fsck is a good test - not so much for the quality of the filesystem
data, but because it checks lots of stuff is correctly installed.)

kre