Upgrading ubuntu

[chinna saaeb]

What does upgrading mean?
does it imply replacing the older packages with new without reinstalling the entire OS or

Reinstalling the new version keeping into view the existing package list.

Can I upgrade the Ubuntu 9.1 amd 64 with Ubuntu 9.1 i386 version using the alternate installation CD

[zvacet]

does it imply replacing the older packages with new without reinstalling the entire OS

Yes,that´s how it works.Replacing old packages with new version of package.You can upgrade package(s) or entire Ubuntu version.For example if you upgrade from Karmic to Lucid you are upgrading entire Ubuntu from one version to another.

You can not upgrade from 9.10amd to 9.10 i386 simply because that is not upgrade.That is just switch from one architecture to another.In this case proper name is fresh install,because you will replace amd for i386.