Fresh and worked instruction
if you want to downgrade from Debian 8 to 7
apt-get install sysvinit sysvinit-core sysvinit-utils cp /usr/share/sysvinit/inittab /etc/inittab
if you want to downgrade from Debian 9 (10) to 7
apt-get install initscripts sysv-rc sysvinit-core sysvinit-utils cp /usr/share/sysvinit/inittab /etc/inittab
Then reboot your server and remove all the systemd stuff!
apt-get remove --purge --auto-remove systemd
Set Apt-Pinning to prevent systemd upgrade mechanism:
echo -e 'Package: systemdnPin: release o=DebiannPin: release *nPin-Priority: -1' > /etc/apt/preferences.d/no-systemd
And continue with the previous downgrade tutorial steps:
First of all you have to remove or replace all Debian tags from your /etc/apt/sources.list to your preffered target release
Mine sources.list file looks like this after changes have made:
deb http://archive.debian.org/debian/ wheezy main contrib non-free deb-src http://archive.debian.org/debian/ wheezy main main contrib non-free deb http://archive.debian.org/debian-security/ wheezy/updates main deb-src http://archive.debian.org/debian-security/ wheezy/updates main
Now we have to use the Apt-Pinning feature to get the correct default release tag for our apt downgrade
Modify or create the file /etc/apt/preferences and put following text in it:
Package: * Pin: release a=stable Pin-Priority: 1001
Important Update note: Replace a=stable with n=wheezy if you are running not the Debian but Jessie final release!
Now for successfully sowngrade we strongly need to create the next file:
with next text:
or run next command:
echo 'Acquire::Check-Valid-Until no;' > /etc/apt/apt.conf.d/99no-check-valid-until
At the next step we have to run the apt update and upgrade process for downgrading all packages
So you will need to enter these two commands to finish the downgrade process:
apt-get update apt-get upgrade apt-get dist-upgrade
Apt will ask you for downgrading all packages now.
Just say yes (Y), let it go and pray that all packages getting installed and downgraded properly!
If some packages failing on downgrade you have to purge them by doing:
apt-get purge your_failing_package