我有一台 Ubuntu 16.04 服务器，自上次重启后，systemctl 不再起作用。
例如如果我想启动 nginx，我会收到以下错误：
root@SERVER:/# systemctl start nginx
Failed to start nginx.service: Unknown unit: nginx.service
对于其他所有服务，结果都相同。只需执行 systemctl 即可得到以下结果：
root@SERVER:/# systemctl
Failed to list units: No such method 'ListUnitsFiltered'
谢谢
apt autoremove
Start-Date: 2016-11-12 20:37:29
Commandline: apt autoremove
Remove: linux-image-4.4.0-38-generic:amd64 (4.4.0-38.57), libsnappy1v5:amd64 (1.1.3-2), libboost-program-options1.58.0:amd64 (1.58.0+dfsg-5ubuntu3.1), linux-image-4.4.0-36-generic:amd64 (4.4.0-36.55), libboost-filesystem1.58.0:amd64 (1.58.0+dfsg-5ubuntu3.1), libv8-3.14.5:amd64 (3.14.5.8-5ubuntu2), linux-headers-4.4.0-36-generic:amd64 (4.4.0-36.55), libboost-thread1.58.0:amd64 (1.58.0+dfsg-5ubuntu3.1), linux-headers-4.4.0-34-generic:amd64 (4.4.0-34.53), linux-headers-4.4.0-38-generic:amd64 (4.4.0-38.57), libboost-system1.58.0:amd64 (1.58.0+dfsg-5ubuntu3.1), linux-image-4.4.0-22-generic:amd64 (4.4.0-22.40), linux-image-4.4.0-42-generic:amd64 (4.4.0-42.62), libtcmalloc-minimal4:amd64 (2.4-0ubuntu5), linux-headers-4.4.0-22:amd64 (4.4.0-22.40), linux-headers-4.4.0-34:amd64 (4.4.0-34.53), linux-headers-4.4.0-36:amd64 (4.4.0-36.55), linux-headers-4.4.0-38:amd64 (4.4.0-38.57), linux-headers-4.4.0-42:amd64 (4.4.0-42.62), linux-headers-4.4.0-22-generic:amd64 (4.4.0-22.40), libgoogle-perftools4:amd64 (2.4-0ubuntu5), linux-headers-4.4.0-42-generic:amd64 (4.4.0-42.62), libunwind8:amd64 (1.1-4.1), libpcrecpp0v5:amd64 (2:8.38-3.1), libyaml-cpp0.5v5:amd64 (0.5.2-3), linux-image-4.4.0-34-generic:amd64 (4.4.0-34.53)
End-Date: 2016-11-12 20:41:18
root@SERVER:/home# dpkg --list | grep systemd
ii libpam-systemd:amd64 229-4ubuntu12 amd64 system and service manager - PAM module
ii libsystemd0:amd64 229-4ubuntu12 amd64 systemd utility library
ii python3-systemd 231-2build1 amd64 Python 3 bindings for systemd
ii systemd 229-4ubuntu12 amd64 system and service manager
ii systemd-shim 9-1bzr4ubuntu1 amd64 shim for systemd