linux是装在虚拟机中的，不知怎么搞的，ssh连接不上，直接登录提示密码错误。只好硬重启。
重启后发现启动不起来，出现上面的提示。百度搜到的内容很少，google又上不去，只好用bing。
最后用光盘启动，chroot了一下，东西还在。重启后，系统又进去了。
[root@localhost ~]# systemctl status systemd-tmpfiles-setup.service
● systemd-tmpfiles-setup.service – Create Volatile Files and Directories
Loaded: loaded (/usr/lib/systemd/system/systemd-tmpfiles-setup.service; static; vendor preset: disabled)
Active: active (exited) since Thu 2016-07-21 10:18:33 CST; 56s ago
Docs: man:tmpfiles.d(5)
man:systemd-tmpfiles(8)
Process: 765 ExecStart=/usr/bin/systemd-tmpfiles –create –remove –boot –exclude-prefix=/dev (code=exited, status=0/SUCCESS)
Main PID: 765 (code=exited, status=0/SUCCESS)
CGroup: /system.slice/systemd-tmpfiles-setup.service
Jul 21 10:18:32 localhost.localdomain systemd[1]: Starting Create Volatile Files and Directories…
Jul 21 10:18:33 localhost.localdomain systemd[1]: Started Create Volatile Files and Directories.
技术更新太快，都跟不上节奏了。
