installing OS over itself

[Nils Kassube]

Robert Holtzman wrote:
> IIRC at one time it was possible to install Ubuntu over a previously
> installed one. Still possible?

It depends on what you mean with "install Ubuntu over a previously 
installed one". You can still from the Live DVD/USB system. If you are 
careful at the partitioning stage, you can select manual partitioning 
and there you can select the partition(s) where you have your installed 
system. Make sure that you keep the file system and DON'T format the 
partition(s).

> If so what is the effect on installed
> apps? I've read a few horror stories about the new install deleting
> the core files, leaving an unbootable computer.

It will remove all system files but the /home and IIRC also /usr/local 
folders are untouched. Usually the system is still bootable. I have done 
that many times and only once there was a problem booting the system 
afterwards. It was a machine with a bad ACPI where I had to select "ACPI 
off" as a kernel boot parameter for the Live DVD already. That parameter 
wasn't automatically included in the grub boot file. I had to manually 
add the parameter at the grub menu and after the successful start I had 
to edit /etc/default/grub to automatically include the parameter in the 
future. Other than that, all your installed applications are gone and 
only the default applications are installed.

Anyway, as always you should make backups before you overwrite your 
system.


Nils