Debian 9 Stretch has been released on 17th June 2016, and you may be now looking for upgrading your previous version, i.e., Debian 8 “Jessie” to the latest version Debian 9 “Stretch“.
This post will guide you through the steps to upgrade your system from Debian 8 “Jessie” to Debian 9 “Stretch”.
Prerequisites:
You need to have an active internet connectivity to download the latest updates.
You must have root or sudo privileges to perform this OS upgrade.
Backup:
Before proceeding to upgrade, request you to take a full backup of important data files and configurations as this may help us restoring the system back to its previous state if you face any issues during the upgrade.
Example,
- Databases
- Configuration files
- Important application data files
Verify the current version:
Use “lsb_release -a” command to see the current version of Debian.
Distributor ID: Debian Description: Debian GNU/Linux 8.8 (jessie) Release: 8.8 Codename: jessie
Update all the packages of Debian 8:
Use the following command to update all the installed packages to the latest package available for the current operating system, i.e., Debian 8 “Jessie”.
apt-get update; apt-get upgrade
Modify /etc/apt/sources.list repository file:
Now edit the Debian apt configuration file “/etc/apt/sources.list” and replace “jessie” with “stretch“. Safer side, take a backup of current sources.lits file.
cp /etc/apt/sources.list /etc/apt/sources.list_bkp
Use “sed” command to update the repository file.
sed -i 's/jessie/stretch/g' /etc/apt/sources.list
The file will look like below after updating it with “stretch”
deb http://deb.debian.org/debian/ stretch main deb-src http://deb.debian.org/debian/ stretch main deb http://security.debian.org/ stretch/updates main deb-src http://security.debian.org/ stretch/updates main deb http://deb.debian.org/debian/ stretch-updates main deb-src http://deb.debian.org/debian/ stretch-updates main
Update the package index.
apt-get update
Preview the upgrade:
Use “apt list –upgradable” command to quickly see what will be installed, updated, and removed during the upgrade process without affecting the system.
apt list --upgradable
Sample Output:
unattended-upgrades/stable 0.93.1+nmu1 all [upgradable from: 0.83.3.2+deb8u1] util-linux/stable 2.29.2-1 amd64 [upgradable from: 2.25.2-6] uuid-runtime/stable 2.29.2-1 amd64 [upgradable from: 2.25.2-6] vim/stable 2:8.0.0197-4 amd64 [upgradable from: 2:7.4.488-7+deb8u3] vim-common/stable 2:8.0.0197-4 amd64 [upgradable from: 2:7.4.488-7+deb8u3] vim-runtime/stable 2:8.0.0197-4 all [upgradable from: 2:7.4.488-7+deb8u3] vim-tiny/stable 2:8.0.0197-4 amd64 [upgradable from: 2:7.4.488-7+deb8u3]
Upgrade to Debian 9 “Stretch”:
Now, update all packages on your system to the latest version available for Debian 9 “Stretch”.
apt-get upgrade
During the package update, you may be asked whether to keep the locally available configuration file intact or replace with the file coming from updated package. Recommendatins is to “keep the local version currently installed“.
Do the distribution upgrade to complete the upgradation to Debian 9.
apt-get dist-upgrade
During the distribution upgrade, services installed on your system needs to be restarted after up gradation of each service packages (ex. Apache, NTP) which may cause you the service interruptions. You can choose to restart automatically during upgrade or manually after the upgrade. Here, I opted to do “an automatic restart of services during the OS upgrade“.
Verify upgrade:
Reboot your machine after the distribution upgrade.
reboot
Verify the current version of Debian operating system.
lsb_release -a
Output:
Distributor ID: Debian Description: Debian GNU/Linux 9.0 (stretch) Release: 9.0 Codename: stretch
That’s All.
