systemd

Known Environment Variables

A number of systemd components take additional runtime parameters via environment variables. Many of these environment variables are not supported at the same level as command line switches and other interfaces are: we don’t document them in the man pages and we make no stability guarantees for them. While they generally are unlikely to be dropped any time soon again, we do not want to guarantee that they stay around for good either.

Below is an (incomprehensive) list of the environment variables understood by the various tools. Note that this list only covers environment variables not documented in the proper man pages.

All tools:

systemctl:

systemd-nspawn:

systemd-logind:

installed systemd tests:

nss-systemd:

systemd-timedated:

systemd-sulogin-shell:

bootctl and other tools that access the EFI System Partition (ESP):

systemd itself: