It is always recommended to upgrade the version to prevent any security vulnerability. You can check the current version of your existing Debian version using this command:
# lsb_release -a
As per the above image, Debian 7.8 (Wheezy) is running. Before running any upgrade, it is vital to take a backup of all the data, such as web content, database, and email accounts. You should take a backup at a third-party backup service or an external drive.
We will upgrade Debian OS step by step, upgrading Debian 7 (Wheezy) to 8 (Jessie), then to 9 (Stretch), and then to 10 (Buster).
Upgrade Debian 7 (Wheezy) to 8 (Jessie)
1. Add the following syntax to /etc/apt/sources.list –
deb http://ftp.debian.org/debian/ jessie main
deb-src http://ftp.debian.org/debian/ jessie main
deb http://security.debian.org/debian-security jessie/updates main
deb http://security.debian.org/ jessie/updates main
deb-src http://security.debian.org/ jessie/updates main
# jessie-updates, previously known as 'volatile'
deb http://ftp.debian.org/debian/ jessie-updates main
deb-src http://ftp.debian.org/debian/ jessie-updates main
2. Update the Debian Package using apt-get.
# apt-get update
# apt-get upgrade
3. Click on Yes to apply service restart during the package upgrade.
4. Dist upgrade will update all the packages to the newest available version.
# apt-get dist-upgrade
5. It will ask to disable SSH password authentication for root.
Set it to No.
6. Reboot the server.
7. Enter this command –
# cat /etc/os-release
8. It will yield the output given below that your version is upgraded to Debian 8 (Jessie)
Debian 8 (Jessie) to 9 (Stretch)
1. Replace the below content at /etc/apt/sources.list
deb http://ftp.debian.org/debian/ stretch main
deb-src http://ftp.debian.org/debian/ stretch main
deb http://security.debian.org/debian-security stretch/updates main
deb http://security.debian.org/ stretch/updates main
deb-src http://security.debian.org/ stretch/updates main
# stretch-updates, previously known as 'volatile'
deb http://ftp.debian.org/debian/ stretch-updates main
deb-src http://ftp.debian.org/debian/ stretch-updates main
2. Update Debian 8 (Jessie) before starting the upgrade process.
# apt-get update
3. We will upgrade the version with the below-given command –
# apt-get upgrade
4. Upgrade packages to the new version with dist.
# apt-get dist-upgrade
5. Reboot the server.
6. Enter the command given below –
# cat /etc/os-release
The output below shows that your version is upgraded to Debian 9 (Stretch) -
Debian 9 (Stretch) to 10 (Buster)
1. Replace the below content at /etc/apt/sources.list
deb http://ftp.debian.org/debian/ buster main
deb-src http://ftp.debian.org/debian/ buster main
deb http://security.debian.org/debian-security buster/updates main
deb http://security.debian.org/ buster/updates main
deb-src http://security.debian.org/ buster/updates main
# buster-updates, previously known as 'volatile'
deb http://ftp.debian.org/debian/ buster-updates main
deb-src http://ftp.debian.org/debian/ buster-updates main
2. Update Debian 9 (Stretch) before starting the upgrade process.
# apt-get update
3. We will upgrade the version with this command –
# apt-get upgrade
4. Upgrade packages to a new version with dist.
# apt-get dist-upgrade
5. Reboot the server.
6. Enter the below-given command –
# cat /etc/os-release
The output below shows that your version is upgraded to Debian 10 (Buster) -
