Seems the mystery was solved: The beeping seems to be caused by brltty. The init.d script reads /etc/default/brltty which has "RUN_BRLTTY=no", so we never actually run this by default. But the systemd unit does start it. Apparently brltty produces the beeps as a kind of notification to blind users, so it sounds plausible that this is deliberate.
So I think what we should do here is to make the systemd unit respect the default file. ** Package changed: systemd (Ubuntu) => brltty (Ubuntu) ** Changed in: brltty (Ubuntu) Status: Confirmed => Triaged -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1316804 Title: loud pc-speaker like beep when rebooting under systemd To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/brltty/+bug/1316804/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs