In the future I have to upgrade several Debian 10 systems to Debian 11. The problem is: The systems have no access to the internet.
What options do I have to upgrade the system?
After some research, I found apt-offline which seemed to be suitable for this task. I tried apt-offline on a fully updated example Debian 10 in the following manner:
- change the /etc/apt/sources.list from buster (Debian 10) to bullseye (Debian 11)
- create apt-offline.sig with :
sudo apt-offline set --upgrade-type dist-upgrade apt-offline.sig
on the online system:
- create bundle.zip with
apt-offline get --bundle bundle.zip apt-offline.sig
on the offline system:
- install bundle with :
sudo apt-offline install bundle.zip
This does not work. apt tries to fetch packages from the internet when apt-get dist-upgrade is performed and the bundle.zip is also only 27Mb big.
It doesn't look like apt-offline is suitable for doing Debian release upgrades.
Is there any other method to perform an offline release upgrade from debian 10 to debian 11?