在我的 Ubuntu 16.04 (Xenial) 服务器上，我无法禁用启动时自动启动的服务。我收到以下错误消息：
$ sudo systemctl disable puppet.service
...
initctl: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused
The script you are attempting to invoke has been converted to an Upstart
job, but lsb-header is not supported for Upstart jobs.
下次启动服务器时，“puppet agent”就会自动运行。
我猜测（根据错误消息）我的服务器处于 systemd（正在运行）和 Upstart 之间的某种奇怪的中间状态。仅供参考，此服务器曾经运行 Ubuntu 14（systemd 之前的版本），现已升级到 15.04、15.10 和 16.04。
看起来 systemd 正在运行，但 upstart 没有运行：
$ ps uax|grep init | grep -v grep
root 1 0.0 0.0 119780 6000 ? Ss May20 0:04 /sbin/init
$ ps uax|grep upstart|grep -v grep
$ ps uax|grep systemd|grep -v grep
root 279 0.0 0.0 35368 3276 ? Ss May20 0:01 /lib/systemd/systemd-journald
root 306 0.0 0.0 45956 5384 ? Ss May20 0:00 /lib/systemd/systemd-udevd
systemd+ 703 0.0 0.0 100324 2532 ? Ssl May20 0:00 /lib/systemd/systemd-timesyncd
root 709 0.0 0.0 20100 2824 ? Ss May20 0:00 /lib/systemd/systemd-logind
root 716 0.0 0.0 29880 1564 ? Ss May20 0:00 /sbin/cgmanager -m name=systemd
message+ 727 0.0 0.0 52848 5668 ? Ss May20 0:00 /usr/bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation
我读过SystemdForUpstartUsers 维基页面并确认软件包systemd-sysv和ubuntu-standard已安装，而未upstart-sysv 安装。因此我似乎拥有正确的软件包。我也在 Google 上搜索过这些错误消息（徒劳无功），但没有找到解决方案。
完整错误信息：
$ sudo systemctl disable puppet.service
Synchronizing state of puppet.service with SysV init with /lib/systemd/systemd-sysv-install...
Executing /lib/systemd/systemd-sysv-install disable puppet
insserv: warning: current start runlevel(s) (empty) of script `puppet' overrides LSB defaults (2 3 4 5).
insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `puppet' overrides LSB defaults (0 1 6).
initctl: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused
The script you are attempting to invoke has been converted to an Upstart
job, but lsb-header is not supported for Upstart jobs.
insserv: warning: script 'screen-cleanup' missing LSB tags and overrides
insserv: Default-Start undefined, assuming empty start runlevel(s) for script `screen-cleanup'
insserv: Default-Stop undefined, assuming empty stop runlevel(s) for script `screen-cleanup'
insserv: warning: current start runlevel(s) (empty) of script `puppet' overrides LSB defaults (2 3 4 5).
insserv: warning: current stop runlevel(s) (0 1 2 3 4 5 6) of script `puppet' overrides LSB defaults (0 1 6).
initctl: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused
The script you are attempting to invoke has been converted to an Upstart
job, but lsb-header is not supported for Upstart jobs.
insserv: warning: script 'screen-cleanup' missing LSB tags and overrides
insserv: Default-Start undefined, assuming empty start runlevel(s) for script `screen-cleanup'
insserv: Default-Stop undefined, assuming empty stop runlevel(s) for script `screen-cleanup'
任何帮助都值得感激！
更新于2016-05-24：
如果我删除相关/etc/init.d脚本（如上/etc/init.d/puppet例所示），错误消息就会消失。想必 systemd 正在使用/lib/systemd/system/puppet.service……？