[HELP] how to upgrade gentoo from x86 to amd64?

figofuture · n00b Joined: 10 Apr 2011 Posts: 4 Location: china

Does anybody know how to upgrade current x86 system to amd64 directly? no need any live cd's help? Thanks.

wswartzendruber · Posted: Sun Apr 10, 2011 8:10 am Post subject:

I believe the general consensus is that reinstalling the whole system takes less work.

devilheart · Posted: Thu Apr 14, 2011 12:49 pm Post subject:

It won't work. Too much work, unless you are willing to get really dirty

chiefbag · Guru Joined: 01 Oct 2010 Posts: 542 Location: The Kingdom

It can't be done.

terminou · Posted: Tue Apr 19, 2011 1:09 pm Post subject:

and you MUST use a liveCD 64 bit when chrooting :wink:

NeddySeagoon · Posted: Tue Apr 19, 2011 5:33 pm Post subject:

figofuture,

Updating from a 32 bit to a 64 bit install is a very long drawn out process. I've seen it documented on these forums once.
The main problems are that you need a 64 bit kernel to get booted to build yourself a 64 bit toolchain in some other location than /

This means you need to use a cross compiler to build the toolchain, the kernel and a few other essential binaries.
Its like a stage1 install only worse.

Further, the on disk layout of 64 bit installs differ. There is both /lib and /lib64.

The only reason for going this route is for the educational experience. A new install is far faster. You can preserve your home, there's not much else you can save. if you have, or can make a spare partition, you can do a dual boot 32 bit/64 bit install and migrate from one to the other. Then destroy the 32 bit install when you no longer need it.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Cyker · Veteran Joined: 15 Jun 2006 Posts: 1746

The misconception with AMD64 is that it's just a superset of x86; It isn't - It is a completely different platform that happens to be able to run x86 instructions.

Trying to upgrade from x86 to AMD64 is more akin to 'upgrading' from x86 to Itanium or PPC or even Sparc! :lol:

desultory · Bodhisattva Joined: 04 Nov 2005 Posts: 9410

devilheart · Posted: Tue May 03, 2011 12:01 pm Post subject:

Toomuch · n00b Joined: 16 Mar 2004 Posts: 49

While I know that this requires a full reinstall, I've been wondering if it would be possible to take the world file and /home (plus possibly parts of /etc) onto a fresh root-partition with a minimal amd64-install and emerge -e from there to get a system that'd be as similar to the current x86 one as possible with minimal hassle. The point being not having to emerge and configure every single program separately afterwards. Is this feasible?

krinn · Watchman Joined: 02 May 2003 Posts: 7471

well never done it myself, and as i have 0 64bits install i might lack some infos, but for me it seems doable to just
- install glibc, gcc, bash & bin-utils tools from 64bits tinderbox binaries, and some other things i don't have in mind right now, but basic tools
- rename /lib to /lib32, create /lib64, symlink that to /lib
and kick off a 64bits livecd, once the hard part is done (having the chroot success), emerge should be able to finish the job.

I'm not sure about success, pretty sure you can keep everything (well, except the /lib, lib32, lib64 difference i don't any others), anyway an interresting experiment, of course not something to play with a server. But looks doable for me.

dE_logics · Advocate Joined: 02 Jan 2009 Posts: 2300 Location: $TERM

I'd like to experiment on this someday.
_________________
My blog