[gentoo-amd64] Re: Can't connect to internet from Live DVD.

[Duncan]

Henry W. Peters posted on Fri, 20 Sep 2013 23:55:01 -0400 as excerpted:

> You mentioned in a previous msg, that it was possible to install Gentoo
> from another "live" DVD/C OS... wondering if you know of any how to do
> links... ?

FWIW, I've only installed from gentoo's live* when working on someone 
else's systems, doing it all as simple as possible "by the handbook", so 
they could see how it all worked.

Back when I first installed gentoo in 2004, I did so from an existing 
Mandrake system, installing gentoo to a different (set of) partition(s).

Since that first time I've not actually done a whole lot of gentoo 
installs, only the (32-bit) netbook.  For it, I created a 32-bit chroot 
on my main system based on the gentoo/amd64 32-bit chroot guide, except 
building the bits (like the kernel and openrc) that would ordinarily not 
need built in a chroot too.  Then I cp-ed the chroot install to an 
external drive and booted it on the target system.  Once booted to the 
external on the target system, I was able to run the usual partitioning 
natively, mount the new internal drive partitions as necessary, and cp 
external -> internal.

Since my main system is vastly more powerful than the netbook, I continue 
to use the chroot build scheme for netbook updates today, doing an rsync 
dry-run first to catch anything that's different between the netbook and 
the chroot-image, resolving any config differences so they're the same on 
both, then doing the update to the chroot and ssh/rsyncing it over to the 
netbook.

Unfortunately I don't keep up with netbook updates like I do the main 
system, so it gets quite behind, often a year or more, so when I *DO* do 
the update, it's a BIG job, often involving intermediate updates and 
reconfiguration in the middle of things so the final update will actually 
complete properly.

But of course not all that's apropos to the current situation.  Anyway, 
yes, installing gentoo from an existing installation or some non-gentoo 
live* isn't particularly hard.  As might be expected on gentoo, there's 
actually instructions! =:^)

The Gentoo Linux alternative installation method HOWTO

http://www.gentoo.org/doc/en/altinstall.xml

Section 3 is Installation from non-Gentoo LiveCDs.
Section 4 is Diskless install using PXE boot.
Section 5 is Installing Gentoo from an existing Linux distribution.

Take your pick! =:^)

Note that in all three cases the instructions substitute a few steps as 
appropriate for those found in the handbook, so you'll need the handbook 
available as well, since after the substituted steps you resume 
installation from the handbook at the appropriate location as instructed. 
That shouldn't be a problem from either an existing install or from most 
non-gentoo live*s as you can simply use the existing browser and net 
connection to read the docs on the gentoo site. =:^)

The other alternative, as mentioned, would be doing a chroot 
installation, much like I did with my netbook, basically following the 32-
bit chroot guide except that it doesn't have to be 32-bit, a 64-bit chroot 
on an existing 64-bit system would work similarly except that you'd run 
linux64 instead of linux32.  And (as I did) you'd install the bits the 
chroot guide skips as well, kernel and openrc, etc, since it won't just 
be a chroot, you'll ultimately be booting it.

(One nice thing about a fully bootable chroot is that if you setup your 
bootloader for it, you can even boot to it instead of the main system on 
the chroot system too.  And if it's a 32-bit chroot that means you can 
run the main system no-multilib as well, since you don't need the 32-bit 
multilib stuff because you have a full 32-bit system in the chroot! =:^)

How to set up a 32bit chroot

http://www.gentoo.org/proj/en/base/amd64/howtos/chroot.xml


You can of course do a chroot without following the guide above, but 
following the guide is nice, as they've already given some thought to 
making the chroot work well with the host system too, with as little 
waste as possible.  For instance, the chroot guide uses a lot of bind-
mounts to mount bits of the main system inside the chroot as well, so 
they don't have to be duplicated, and cps other things.  That's a nice 
touch, and it gives you a bit of flexibility too, since you can simply 
choose not to bind-mount or copy bits that differ enough between the host 
system and the ultimate target to screw things up. =:^)  (Things like
/sys and /proc shouldn't matter, however, since in chroot mode you don't 
actually run the kernel you build in the chroot, and you'll want to 
configure and build the kernel for the target system without referring to 
the hosts /proc and /sys files.  So those can be mounted from the host 
without interfering with the target system, as long as you don't use them 
to setup your kernel config.)

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman