Re: New boothowto flag to prevent raid auto-root-configuration

[Greg Oster <oster%cs.usask.ca@localhost>]

On Mon, 18 Apr 2011 13:06:23 +0200
"Klaus . Heinz" <k.heinz%aprelf.kh-22.de@localhost> wrote:

> Martin Husemann wrote:
> 
> > as described in PR 44774 (see
> > http://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=44774),
> > it is currently not possible to use a standard NetBSD install CD on
> > a system wich normally boots from raid (at least on i386, amd64 or
> > sparc64, where a stock GENERIC kernel is used).
> 
> It looks like this is a similar problem to the one I raised here
> 
>   http://mail-index.NetBSD.org/tech-kern/2009/10/31/msg006410.html
> 
> Instead of providing RB_NO_ROOT_OVERRIDE I would prefer something that
> actually _lets_ me override everything else from boot.cfg.

So how about adding another flag like RB_ROOT_EXPLICIT OR
RB_EXPLICIT_ROOT with the idea being that the user has to explicitly
specify what the root is going to be?  I think that addresses 1) below
and would hopefully handle the pxeboot and NFS root situations.  Maybe
something like "RB_SET_ROOT" with a required option of "NFS" or "raid0"
or "wd0a" or "pxe" or whatever would be the way to go?

I've never liked the 'yank root away from the boot device that the
system thinks it maybe booted from' hack in RAIDframe, so anything we
can do to make it better is fine by me....

We may need both RB_NO_ROOT_OVERRIDE and this new flag in order to get
everything covered, and I'm fine with that too...

> Quoting Robert Elz from the mentioned thread:
> 
> > FWIW, I think the code to allow the user to override that at boot
> > time would be a useful addition - while it is possible to boot,
> > "raidctl -A yes" or "raidctl -A no", and then reboot, or perhaps
> > "boot -a" on systems that support that, but that's a painful
> > sequence of operations for what should be a simple task.
> > 
> > It should always be
> >       1. what the user explicitly asks for
> >       2. what the kernel has built in
> >       3. hacks like "ratdctl -A root" (or perhaps similar things
> > for cgd etc) 4. where I think I came from
> 
> 
> ciao
>      Klaus


Later...

Greg Oster