服务器重启后vncviewer连接远程桌面时失败，SSH连接服务器发现 vncserver 没有自动启动，于是手动启动 vncserver 服务报如下错误：

[root@www ~]# systemctl start vncserver@:1.service
Job for vncserver@:1.service failed because a configured resource limit was exceeded. See "systemctl status vncserver@:1.service" and "journalctl -xe" for details.
[root@www ~]# systemctl status vncserver@:1.service
● vncserver@:1.service - Remote desktop service (VNC)
   Loaded: loaded (/etc/systemd/system/vncserver@:1.service; enabled; vendor preset: disabled)
   Active: failed (Result: resources) since Thu 2019-08-01 16:43:01 CST; 12s ago
  Process: 4705 ExecStart=/usr/sbin/runuser -l root -c /usr/bin/vncserver %i (code=exited, status=0/SUCCESS)
  Process: 4701 ExecStartPre=/bin/sh -c /usr/bin/vncserver -kill %i > /dev/null 2>&1 || : (code=exited, status=0/SUCCESS)

Aug 01 16:42:57 www systemd[1]: Starting Remote desktop service (VNC)...
Aug 01 16:43:01 www systemd[1]: PID file /root/.vnc/www:1.pid not readable (yet?) after start.
Aug 01 16:43:01 www systemd[1]: Failed to start Remote desktop service (VNC).
Aug 01 16:43:01 www systemd[1]: Unit vncserver@:1.service entered failed state.
Aug 01 16:43:01 www systemd[1]: vncserver@:1.service failed.

尝试第二种方式开启 vnc 服务：

vncserver

交互如下：

[root@www tmp]# vncserver

Warning: www:1 is taken because of /tmp/.X11-unix/X1
Remove this file if there is no X server www:1

Warning: www:5 is taken because of /tmp/.X11-unix/X5
Remove this file if there is no X server www:5

New 'www:7 (root)' desktop is www:7

Starting applications specified in /root/.vnc/xstartup
Log file is /root/.vnc/www:7.log

发现 pid1 和 5 被占用了，警告里写的很清楚了，如果没运行此服务，删除文件 /tmp/.X11-unix/X1 ：

[root@www .vnc]# rm -rf ~/.vnc/www\:1.pid 
[root@www tmp]# rm -rf /tmp/.X11-unix/X1

再次启动服务

[root@www tmp]# systemctl start vncserver@:1.service

成功！