I have been reading up and investigating systemd and systemctl on Debian 8 Jessie.

When running

$ sudo systemctl list-units --all --type=service

a few services appear in the list that have no unit-file associated to them such as:

● clamav-daemon.service | not-found | inactive | dead | clamav-daemon.service

● console-screen.service | not-found | inactive | dead | console-screen.service

● festival.service | not-found | inactive | dead | festival.service

● greylist.service | not-found | inactive | dead | greylist.service

● keymap.service | not-found | inactive | dead | keymap.service

● krb5-kdc.service | not-found | inactive | dead | krb5-kdc.service

Yet at the same time, when running

$ sudo systemctl list-unit-files --all --type=service

there are no unit-files associated to the above units.

My question is:

How can systemctl list these services as units (or even know that these units exist), if there are no unit-files that exist for these units?

  • serverfault.com/a/836992/229499
    – muru
    Commented Mar 5, 2020 at 16:02
  • @muru thats it after doing a little probing with grep I found that all these services were listed in SysVinit scripts in /etc/init.d. Being backwards compatible, systemd also initialises the scripts located in this folder. Good catch! Commented Mar 5, 2020 at 16:38

1 Answer 1


Some unit "files" are created on the fly (for example for devices, their entries are also created by the kernel as the devices get initialized), and only ever exist in memory.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .