The source of this tutorial is sysadminslife.com1) and describes the update process in a compact form.
Before you start the update, you should definitely start a data backup. Ideally, create a snapshot or a hard disc image. (I will not go into the procedure here)
cat /etc/debian_version 6.0.7
apt-get update apt-get upgrade apt-get dist-upgrade
Adapt the file /etc/apt/sources.list as follows (if there are entries from third-party providers, these must also be updated):
deb http://ftp.at.debian.org/debian/ wheezy main deb-src http://ftp.at.debian.org/debian/ wheezy main deb http://security.debian.org/ wheezy/updates main deb-src http://security.debian.org/ wheezy/updates main deb http://ftp.at.debian.org/debian/ wheezy-updates main deb-src http://ftp.at.debian.org/debian/ wheezy-updates main
apt-get update apt-get upgrade
List the current kernel:
dpkg -l | grep linux-image
Sample output:
ii linux-image-2.6-amd64 2.6.32+29 Linux 2.6 for 64-bit PCs (meta-package) ii linux-image-2.6.32-5-amd64 2.6.32-41 Linux 2.6.32 for 64-bit PCs
Here you have to remember the meta designation (amd64 or 686):
apt-get install linux-image-2.6-amd64
update-grub
apt-get install udev
apt-get dist-upgrade
cat /etc/debian_version 7.0
shutdown -r now
Be sure to check the error logs!