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

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

[Helmut Jarausch]

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?

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.

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

[J. Roeleveld]

On Tuesday 16 November 2010 10:33:34 Helmut Jarausch wrote:
> 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?
> 
> 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.

Ok, the following is NOT tested, but might work:
1) boot with a systemrescuecd
2) backup the sytem (I did not test this)
3) create a chroot-space for a new install (don't worry, not doing full 
install)
4) unpack a stage3
5) chroot into this
6) build packages from this stage3
7) chroot into the install to be fixed
8) emerge these packages onto your current system (this should contain all you 
need for "system")
9) emerge -e world

If there is anyone who has actually been in this situation, please feel free 
to comment on this.
Also, I'm not certain what will happen to /etc, but the etc-update script can 
be told to keep existing configurations.

--
Joost

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

[Alan McKinnon]

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

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

[Helmut Jarausch]

On 11/16/10 10:56:29, Alan McKinnon wrote:
> 
> 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.
> 

Thanks Alan,

just one more question: where are information like the
current eselect(ions) stored?

Helmut.

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

[Marius Vaitiekunas]

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Hello,

I think You could try:
1) change cflags in make.conf
2) bootstrap.sh
3) emerge -e system
4) emerge -e world

In other words this is how to build a system from stage 1.

On Tue, Nov 16, 2010 at 12:06 PM, Helmut Jarausch <
jarausch@igpm.rwth-aachen.de> wrote:

> On 11/16/10 10:56:29, Alan McKinnon wrote:
> >
> > 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.
> >
>
> Thanks Alan,
>
> just one more question: where are information like the
> current eselect(ions) stored?
>
> Helmut.
>
>


-- 
mv

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

[Alan McKinnon]

Apparently, though unproven, at 12:06 on Tuesday 16 November 2010, Helmut 
Jarausch did opine thusly:

> On 11/16/10 10:56:29, Alan McKinnon wrote:
> > 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.
> 
> Thanks Alan,
> 
> just one more question: where are information like the
> current eselect(ions) stored?

I've never found a place where eselect stores it's info. I suspect it directly 
reads all the various symlinks off disk when it starts up. If so, this will 
cause you some extra manual work.




-- 
alan dot mckinnon at gmail dot com

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

[Adam Carter]

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> 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.
>

Did you have -march set? If so, what to?

If -march is unset, then AFAIK your binaries should run on any amd64
machine. If you have it set to native, then your binaries will only run on
equal or greater hardware than what it was built on.

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

[Helmut Jarausch]

On 11/17/10 00:01:15, Adam Carter wrote:
> > 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.
> >
> 
> Did you have -march set? If so, what to?
> 
> If -march is unset, then AFAIK your binaries should run on any amd64
> machine. If you have it set to native, then your binaries will only
> run on
> equal or greater hardware than what it was built on.

Thanks Alan. I knew that, but then I inherited an somewhat older 
Opteron machine and I wasn't aware that this one had a different 
instruction set then current Opterons.

Helmut.




-- 
Helmut Jarausch
Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany