After release of Debian 6.0 (squeeze) the question of how to upgrade from previous version to the latest.

It appears to be fairly simple process:

1. Edit sources.list

vi /etc/apt/sources.list

2. Replace distribution name (I appeared to have Lenny) with Squeeze.

%s/lenny/squeeze/g

Note: DebianVolatile has been superseded by squeeze-updates since Debian Squeeze.

To use squeeze-updates just add

deb http://mirrors.kernel.org/debian squeeze-updates main contrib

to sources.list

Then as usual:

apt-get update
apt-get dist-upgrade