Degrade, upgrade

[Paul Mather]

On Thu, 2004-07-22 at 09:06, Kovács Péter wrote:
> Hello guys,
> 
> I have a system running FreeBSD 5.2.1 and want to degrade it
> to FreeBSD 4.10 (because the program I want to use only runs
> and supported on that platform) without reinstalling the system.
> Is it enough to cvsup to the RELENG_4 branch and recompile
> the system?
> Should I recompile all the programs that were previously
> compiled in the FreeBSD 5 environment?
> 
> I would also like to know how this works backwards (which is
> the common way), so to upgrade from 4 to branch 5. Is there
> some kind of tutorial for this?

I doubt there is a tutorial because, so far as I know, downgrading is
neither officially supported nor guaranteed to work.  (I'd say this is
especially true when jumping down major release numbers.)

In the case of going from 5.2.1 -> 4.10 it's likely to be doomed
immediately because 5.2.1 uses UFS2 by default during installation. 
UFS2 is not supported in 4.10.  So, unless you happen to be using UFS1
filesystems on your system being downgraded, the 4.10 kernel will choke.
(See http://sixshooter.v6.thrupoint.net/jeroen/faq.html for a UFS2 FAQ.)

Given you'd have to dump/newfs/restore anyway, folks will tell you it'd
be easier to do a clean install of 4.10, too.

Good luck!

Cheers,

Paul.
-- 
e-mail: paul at gromit.dlib.vt.edu

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