A month ago Debian 7.0 (Wheezy) Stable was released. Today I will teach you how to upgrade Debian 6 (Squeeze) to Debian 7 (Wheezy).
This tutorial works on 32 / 64 bit architectures.
Open your list of repositories:
# vi /etc/apt/sources.list
Remove all Squeeze repositories and add the repositories for Wheezy:
deb http://mirrors.kernel.org/debian/ wheezy main deb-src http://mirrors.kernel.org/debian/ wheezy main deb http://security.debian.org/ wheezy/updates main deb-src http://security.debian.org/ wheezy/updates main # wheezy-updates, previously known as 'volatile' deb http://mirrors.kernel.org/debian/ wheezy-updates main deb-src http://mirrors.kernel.org/debian/ wheezy-updates main
Update the list of packages:
# apt-get update
Update the system:
# apt-get upgrade
Update the distro:
# apt-get dist-upgrade
That’s it. Now restart the system and check the new version:
$ lsb_release -a
Source: http://www.cyberciti.biz/faq/howto-debian-linux-upgrade-6-squeeze-to-7-wheezy/
