I am wary of systemd for various reasons which are irrelevant to this question. Now, I'm about to upgrade my Debian Wheezy to Debian Jessie. Will systemd be used by default after an apt-get dist-upgrade? If so, what do I need to do to stick with sysvinit?
Yes, it will run by default. A dist-upgrade from wheezy to Jessie will switch to using
systemd as the init system. The Jessie release notes devotes a whole section to this issue, also giving a recommendation about how to stay with your current init system:
systemd-sysvfrom being installed during the upgrade, you can create a file called
/etc/apt/preferences.d/local-pin-initwith the following contents:
Package: systemd-sysv Pin: release o=Debian Pin-Priority: -1
It also mentions that "some packages may have degraded behavior or may be lacking features under a non-default init system."
Jessie will install
systemd by default, even as an upgrade from Wheezy. After installation you can disable it by following the instructions at How to remove systemd from a Debian jessie/sid installation
There are explanations of these commands on that page, but the gist is as follows:
apt-get install sysvinit-core sysvinit sysvinit-utils reboot # BE AWARE that the following command removes packages that depend on systemd itself or things like libpam-systemd! apt-get remove --purge --auto-remove systemd # These prevent systemd in the future. Unfortunately also including systemd-shim echo -e 'Package: systemd\nPin: origin ""\nPin-Priority: -1' > /etc/apt/preferences.d/systemd echo -e '\n\nPackage: *systemd*\nPin: origin ""\nPin-Priority: -1' >> /etc/apt/preferences.d/systemd echo -e '\nPackage: systemd:amd64\nPin: origin ""\nPin-Priority: -1' >> /etc/apt/preferences.d/systemd echo -e '\nPackage: systemd:i386\nPin: origin ""\nPin-Priority: -1' >> /etc/apt/preferences.d/systemd