This article describes an upgrade procedure from Debian Wheezy to Debian Jessie. Debian Linux with a code name “Jessie” is the latest stable Debian release which succeeds previous stable version “Wheezy”.
It is important to point out that nothing is bulletproof and proper failover procedure should be discussed before the upgrade takes place. The rule of thumb is, the less software is installed on your system the higher chance for a successful upgrade. Before you move on with the upgrade consider the following recommendations.
1. Upgrade Recommendations
Remove unnecessary packages
Fully upgrade your current system
Make a data backup
Although there should not be a problem to perform update via SSH. If possible it is recommended to perform upgrade directly using console
2. Fully Upgrade current System
First, fully upgrade your current Wheezy Debian system:
# apt-get update
# apt-get upgrade
# apt-get dist-upgrade
3. Upgrade to Debian Jessie
Once the above upgrade is finished update /etc/apt/sources.list:
# sed -i 's/wheezy/jessie/g' /etc/apt/sources.list
For example:
FROM DEBIAN WHEEZY:
# cat /etc/apt/sources.list
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 main contrib non-free
deb-src http://ftp.at.debian.org/debian/ wheezy main contrib non-free
TO DEBIAN JESSIE
deb http://security.debian.org/ jessie/updates main
deb-src http://security.debian.org/ jessie/updates main
deb http://ftp.at.debian.org/debian/ jessie main contrib non-free
deb-src http://ftp.at.debian.org/debian/ jessie main contrib non-free
At this stage we are ready to upgrade packages:
# apt-get update
# apt-get upgrade
During the upgrade you may be given an option to manually or automatically restart any currently running services. The recommended strategy is to do manual restart as it provides more flexibility. If you are running SSH service you will be also given an option to disable SSH root access. What it means, that if you opt to “YES” you will no longer be able to SSH login as root user.
If there are no issues with the package upgrade we are ready to perform a full system distribution upgrade from Debian Wheezy to Debian Jessie.
# apt-get dist-upgrade
After the upgrade it is recommended to reboot your system:
# reboot
Check your upgrade:
root@debian:~# hostnamectl
Static hostname: debian
Icon name: computer-vm
Chassis: vm
Machine ID: 909d78b4d6cd403bb9cf478d1a3fb18d
Boot ID: 17584ebda9d447cc9657fcbced3850d0
Virtualization: oracle
Operating System: Debian GNU/Linux 8 (jessie)
Kernel: Linux 3.16.0-4-amd64
Architecture: x86-64
Fuente: https://linuxconfig.org/how-to-upgrade-debian-linux-system-from-wheezy-to-jessie-stable-release el 15 de junio de 2016