fresh install over ssh

[Patrick Asselman]

Good afternoon all,

I have a remote server that I wish to reinstall. It is running a 32 bit 
Ubuntu 12.04.2LTS (server) but it should have been running a 64 bit 
version instead. (The 32 bit version suffers from oom-killer shooting 
down random processes as soon as it is doing what it is supposed to do, 
which is handle some large databases).

So I found this guide to install Ubuntu via ssh: 
https://help.ubuntu.com/community/Installation/OverSSH

What I don't grasp is: at what point does the system know to boot the 
new system instead of the currently running system? I would expect an 
edit in /etc/fstab or some LILO or GRUB configuration editing, but all I 
see is stuff that is done in the new /mnt/ubuntu chroot environment, and 
then a reboot. Doesn't the reboot simply bring the old system back up, 
without touching the newly created chroot environment?


Or does anyone have a better idea on how to get a 64 bit Ubuntu on the 
server from a remote location?


(And don't worry, I know this is difficult and risky and that I may 
need to go to the remote location with an install CD to correct things. 
But I'm trying to prevent that... we'll see how it goes, I have nothing 
to lose.)


Best regards,
Patrick Asselman