Re: [gentoo-user] how to rebuild gentoo on a somewhat different hardware

[Alan McKinnon <alan.mckinnon@gmail.com>]

Apparently, though unproven, at 11:33 on Tuesday 16 November 2010, Helmut 
Jarausch did opine thusly:

> Hi,
> 
> I have an up-to-date ~amd64 GenToo installation with has been
> built on a current AMD64 (Phenom II) machine where I used
> -mtune=native in etc/make.conf since I didn't think of the case
> that I would need to port this system to a somewhat older Opteron
> based machine (still AMD64)
> 
> But after cloning the system, some fundamental utilities die of
> an illegal instruction. So I have to rebuild GenToo nearly
> from scratch. emerge -e world doesn't work.
> 
> So, what is a reasonably fast method?

Backup your portage related data and re-install.

Seriously - you know you are looking at doing emerge -e world and will need to 
fiddle stuff to make it complete successfully.

If you just reinstall, put your old world file and /etc/portage/ back then let 
portage have at it, that is exactly what will happen. You'll have 30-45 
minutes of setup work and a high level of confidence it will complete 
successfully.

Trying to fix the existing installation is potentially many hours of poking 
around to see what changed, potentially several goes at running emerge -e 
world, hair pulling, and you will probably give up and just reinstall anyway.

I'm assuming you are looking for the easiest, fastest route to success with 
the least pain, and that your days of poking into portage to see how things 
work for fun are long over.



> 
> I'd like to keep
> /etc
> /usr/portage   except /usr/portage/packages
> /var/lib/portage
> 
> Is there a fast method e.g. by using the Gentoo based
> SystemRescueCD to reinstall a very basic system, such that
> I can do  emerge -e world.
> It looks as if the gcc tool-chain is intact since I could
> compile a kernel without any problem.
> But some utilities, e.g. find, die of an illegal instruction.
> 
> Many thanks for any hints saving me a couple of hours work,
> 
> Helmut.

-- 
alan dot mckinnon at gmail dot com