Debian 9 Stretch is the next future stable version of Debian, but although it is not currently recommended by the Debian team, the truth is that the version is stable enough to use it on our production teams.
Even the testing version of Debian is considered by many to be a version suitable for use on production machines . That's why we're going to show you how to upgrade from your current Debian 8 Jessie to the new Debian 9 Stretch.
Debian 9 Stretch will be the future stable version of Debian
First, we need to make sure we have the latest version of Debian (currently Debian 8.8). To do this, open the terminal and type the following:
sudo apt-get update sudo apt-get upgrade sudo apt-get dist-upgrade
Once we've done this, we need to update the distribution's repositories . To do this, we type the following in the terminal:
sudo nano /etc/apt/sources.list
This will open the Nano text editor and the sources.list file containing the Debian repositories. Now we need to change the text in the lines where the word "Jessie" appears and replace it with the word "Stretch". After doing so, we need to save the changes. To do this, simply press Control + O and then exit by pressing Control + X. Now we need to repeat the first step. To do this, open the terminal and type the following again:
sudo apt-get update sudo apt-get upgrade sudo apt-get dist-upgrade
After this, the distribution should begin updating to the new version, an update that contains hundreds of packages and requires a high-speed connection ; otherwise, the process could take hours. An alternative would be to use the Debian 9 Stretch ISO image , but to do so, you would need to download the image from this link and modify the repositories to use the ISO image.