Thanks to some help in #systemd I could find the cause: On the affected systems libpam-systemd was not installed. So maybe it would make sensu to turn this into a stronger dependency than "recommended", at least in combination with openssh-server.
-- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/1564451 Title: User processes are counted towards systemd limit for sshd processes To manage notifications about this bug go to: https://bugs.launchpad.net/systemd/+bug/1564451/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs