在启动时，我收到一条错误消息[failed] failed to start apply Kernel variables。到目前为止，我还没有使用过 Systemd 发行版，所以我不确定我应该寻找什么。
我在终端运行此程序并得到以下结果：
systemd-sysctl.service - Apply Kernel Variables
Loaded: loaded (/lib/systemd/system/systemd-sysctl.service; static; vendor preset: enabled)
Active: failed (Result: exit-code) since Sat 2016-04-30 13:40:13 EDT; 26min ago
Docs: man:systemd-sysctl.service(8)
man:sysctl.d(5)
Process: 546 ExecStart=/lib/systemd/systemd-sysctl (code=exited, status=1/FAILURE)
Main PID: 546 (code=exited, status=1/FAILURE)
Apr 30 13:40:13 ced-XPS-8700 systemd[1]: Starting Apply Kernel Variables...
Apr 30 13:40:13 ced-XPS-8700 systemd[1]: systemd-sysctl.service: Main process exited, code=exited, status=1/FAILURE
Apr 30 13:40:13 ced-XPS-8700 systemd[1]: Failed to start Apply Kernel Variables.
Apr 30 13:40:13 ced-XPS-8700 systemd[1]: systemd-sysctl.service: Unit entered failed state.
Apr 30 13:40:13 ced-XPS-8700 systemd[1]: systemd-sysctl.service: Failed with result 'exit-code'.