[Cialug] migrating from ubuntu server to debian

[Matthew Nuzum]

Hi Paul, you're memory is pretty good. I've tweaked a few things and
once I'm done I'll reply w/ the exact steps I used and know work.

I'm in the chroot section trying to decide if I need an initrd and
noticed that /boot is completely empty. This implies I'm going to need
something, I think. Any suggestions on what? Does apt-get install
linux-image-2.6... sound right?

Also, I'm wondering if I can get some assistance deciding what to do
about grub. If something goes wrong it'd be great to tell the local
admin, "just reboot and choose this from the menu." I'm not planning
on ever booting into the original fs once this is working (but I need
to recover some data from it first). Any suggestions?

On Wed, Mar 24, 2010 at 8:09 AM, Paul Gray <gray at cs.uni.edu> wrote:
> Matthew Nuzum wrote:
>> Hi, I have a server running Ubuntu 9.04 server. I'm trying to run
>> software that's not well supported in Ubuntu but is well supported in
>> Debian. I was wondering if anyone has any suggestions for switching.
>>
>> There's a catch - I have no physical access to the server. :-/
>>
>> I'm doing a test now in virtualbox but if anyone has any experience
>> I'd appreciate it. The ideas that come to mind are:
>>
>> 1. use dist-upgrade after changing the sources.list to point to debian
>> 2. try to trigger the installer from a mounted ISO
>>
>> I'm OK with either option. I have a 90GB filesystem on a 500GB drive
>> using LVM. Does that give anyone any ideas?
>
> You might be better served using debootstrap.  You can use debootstrap from
> within Ubuntu to install Debian.
>
> Since you're using LVM, you can carve out a small partition (4GB) for the root
> Debian image, and dual boot your Ubuntu system alongside the Debian install
> system while you're troubleshooting the migration. (I'm wasn't sure if you were
> intending the entire 90GB LVM for Debian, or if that's what your current Ubuntu
> install is using.  If it's in use, 4GB is fine for a base install.)
>
> Debootstrap is quite easy to use to pull in a base Debian installation.  The
> only real gotcha's are setting root password, configuring networking, and
> starting up ssh.
>
> To start off, mount the Debian-to-be partition, under /target for example, and
> issue:
>   debootstrap lenny /target http://debian.cns.uni.edu
>
> Let it grind for a while.  Afterwards, (this is from memory, so take it with a
> grain of salt):
>   mount --bind /dev /target /dev
>   chroot /target
>   # Now fix things in the target image so that you can boot it up and get in.
>   mount -t proc none proc /proc
>   mount -t devpts none /dev/pts
>   apt-get install ssh locales initramfs-tools
>   passwd
>   vi /etc/network/interfaces  # define eth0 as appropriate
>   # finally... You MAY need to generate an initrd
>   mkinitramfs -o /boot/initrd.img-`uname -r` `uname -r`
>   # Then, you need to decide which system is going to maintain your grub setup
>   # ... optional ...
>   apt-get install grub
>   # then fix grub.
>
> Hope that I haven't missed any steps, but the above outline should get you
> through the bulk of the transition....at least enough to play with on your VBox
> environment.
>
> --
> Paul Gray                                         -o)
> 314 East Gym, Dept. of Computer Science           /\\
> University of Northern Iowa                      _\_V
>  Message void if penguin violated ...  Don't mess with the penguin
>  No one says, "Hey, I can't read that ASCII attachment ya sent me."
> _______________________________________________
> Cialug mailing list
> Cialug at cialug.org
> http://cialug.org/mailman/listinfo/cialug
>



-- 
Matthew Nuzum
newz2000 on freenode, skype, linkedin, identi.ca and twitter