Subject: Re: netbsd-2-0/200403310000/sparc GENERIC.MP
To: Martin Husemann <martin@duskware.de>
From: Simon J. Gerraty <sjg@crufty.net>
List: tech-smp
Date: 04/12/2004 14:10:25
On Mon, 12 Apr 2004 10:23:56 +0200, Martin Husemann writes:
>On Sun, Apr 11, 2004 at 09:40:44AM -0700, Simon J. Gerraty wrote:
>> Hmmm so its impossible to do test boots of 2.0 or current on
>> a 1.6.2 box?
>
>No. Thanks to Darrin's work you can now exactly do that.
>I just tested it: create a file system on 1.6.2, boot 2.0_BETA, fsck -f
>the new file system - just works, no complaints.

Ok cool - and 1.6.2 will still be happy with the fs?

>But: if you have test booted a -current kernel in the broken period between
>import of the FFSv2 changes and Darrins fixes to it, the -current kernel
>will have munged your super block in a way that 1.6.2  ignores. This was
>a bug. And it's unrecoverable, unless someone volunteers to write code
>to downgrade the superblocks from the munged state to the old (pre
>FFSv2-import) state.

Rats...  probably not a huge deal for me - there's next to nothing on
this box that can't be regenerated...
If 1.6.2 will be ok with fs after 2.0 has touched it, then I'll simply
re-install 1.6.2

Thanks
--sjg