Upgrade Debian

Currently most relevant upgrade is Bookworm to Trixie

NOT DONE YET…

Bullseye to Bookworm (old)

The main aproach is being cautios, and considering if the install is pure Debian, or there are special things added.

Otherwise the quick and dirty route is:

apt list '~o'

And remove if they are not essential:

apt purge '~o'

find /etc -name '*.dpkg-*' -o -name '*.ucf-*' -o -name '*.merge-error'

Check that GPG is installed:

apt install gpgv

Check packages:

dpkg --audit

Change bullseye to bookworm in all of:

/etc/apt/sources.list
/etc/apt/sources.list.d/*

Unless there is a good reason not to.

Special for bookworm is that firmware has move to it’s own component, so to be safe add it to the “main” debian deb:

deb https://deb.debian.org/debian bullseye main contrib non-free

Like this

deb https://deb.debian.org/debian bookworm main contrib non-free non-free-firmware

Update, and watch out for failures:

apt update

It is recommended to record a script:

script -t 2>~/upgrade-bookworm1.time -a ~/upgrade-bookworm1.script

Increment the number every time, so they do not get overridden.

Check that there is enough free space:

apt -o APT::Get::Trivial-Only=true full-upgrade

It will fail with:

E: You don't have enough free space in /var/cache/apt/archives/.

First one without installing new packages:

apt upgrade --without-new-pkgs

If that all looks good, go for full upgrade:

apt full-upgrade

When confident and ready, do a reboot!