原文链接：https://www.cnblogs.com/kevingrace/p/5821450.html
不做过多介绍了，下面直接记录下centos7系统下安装配置vncserver的操作记录
0）更改为启动桌面或命令行模式
获取当前系统启动模式
[root@localhost ~]# systemctl get-default
multi-user.target
查看配置文件
[root@localhost ~]# cat /etc/inittab
# inittab is no longer used when using systemd.
#
# ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
#
# Ctrl-Alt-Delete is handled by /usr/lib/systemd/system/ctrl-alt-del.target
#
# systemd uses 'targets' instead of runlevels. By default, there are two main targets:
#
# multi-user.target: analogous to runlevel 3 //命令行模式
# graphical.target: analogous to runlevel 5 //图形界面模式
#
# To view current default target, run:
# systemctl get-default
#
# To set a default target, run:
# systemctl set-default TARGET.target
#
[root@localhost ~]# systemctl set-default graphical.target //由命令行模式更改为图形界面模式
[root@localhost ~]# systemctl set-default multi-user.target //由图形界面模式更改为命令行模式
[root@localhost ~]# systemctl get-default
graphical.target
1）关闭防火墙
centos的防火墙是firewalld，关闭防火墙的命令
[root@localhost ~]# systemctl stop firewalld.service #停止firewall
[root@localhost ~]# systemctl disable firewalld.service #禁止firewall开机启动
[root@localhost ~]# setenforce 0
[root@localhost ~]# getenforce
[root@localhost ~]# cat /etc/sysconfig/selinux
SELINUX=disabled
SELINUXTYPE=targeted
2）安装软件：
[root@localhost ~]# yum update
[root@localhost ~]# yum groupinstall "GNOME Desktop" "X Window System" "Desktop"
[root@localhost ~]# yum install tigervnc-server tigervnc vnc vnc-server
3）配置vnc连接
[root@localhost ~]# cp /lib/systemd/system/[email protected] /etc/systemd/system/vncserver@:1.service
修改/etc/systemd/system/vncserver@:1.service
找到这一行
ExecStart=/sbin/runuser -l -c "/usr/bin/vncserver %i"
PIDFile=/home//.vnc/%H%i.pid
这里直接用root 用户登录，所以我替换成
ExecStart=/sbin/runuser -l root -c "/usr/bin/vncserver %i"
PIDFile=/root/.vnc/%H%i.pid
如果是其他用户的话比如john替换如下
ExecStart=/sbin/runuser -l john -c "/usr/bin/vncserver %i"
PIDFile=/home/john/.vnc/%H%i.pid
由于直接root用户登录，所以配置如下：
[root@localhost ~]# cat /etc/systemd/system/vncserver@:1.service
.........
[Unit]
Description=Remote desktop service (VNC)
After=syslog.target network.target
[Service]
Type=forking
# Clean any existing files in /tmp/.X11-unix environment
ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
ExecStart=/usr/sbin/runuser -l root -c "/usr/bin/vncserver %i"
PIDFile=/root/.vnc/%H%i.pid
ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
[Install]
WantedBy=multi-user.target
为VNC设密码（比如密码设置为123456）
[root@localhost ~]# vncpasswd
Password:
Verify:
Would you like to enter a view-only password (y/n)? n#注意表示"是否输入一个只能查看的密码，选择否",否则连接vnc会出现黑屏
A view-only password is not used
[root@localhost ~]# vim /etc/libvirt/qemu.conf
vnc_password = "123456"
vnc_listen = "0.0.0.0"
重加载 systemd
[root@localhost ~]# systemctl daemon-reload
启动vnc
[root@localhost ~]# systemctl enable vncserver@:1.service
[root@localhost ~]# systemctl start vncserver@:1.service
注意，此处关闭了防火墙
如果防火墙开了，需要开通一下规则：
[root@localhost ~]# firewall-cmd --permanent --add-service vnc-server
[root@localhost ~]# systemctl restart firewalld.service
如果是iptable，则需要在/etc/sysconfig/iptables里添加：
-A INPUT -m state --state NEW -m tcp -p tcp --dport 5900:5903 -j ACCEPT
关闭vnc连接
[root@localhost ~]# /usr/bin/vncserver -kill :1
测试vnc连接：
[root@localhost ~]# novnc_server --vnc 192.168.1.8:5901 --listen 6081
Warning: could not find self.pem
Starting webserver and WebSockets proxy on port 6081
WebSocket server settings:
- Listen on :6081
- Flash security policy server
- Web server. Web root: /usr/share/novnc
- No SSL/TLS support (no cert file)
- proxying from :6081 to 192.168.1.8:5901
Navigate to this URL:
http://kvm-server:6081/vnc.html?host=kvm-server&port=6081 #http访问方式
Press Ctrl-C to exit
由于kvm-server的主机名对于ip是112.112.113.56，所以在浏览器里输入：
http://112.112.113.56:6081/vnc.html?host=112.112.113.56&port=6081
也可以在本地windows机器上安装vnc viewer，远程访问
在windows下安装vnc客户端，
下载地址：https://pan.baidu.com/s/1hrSIr4K
提取密码：dqdt
VNC远程连接信息（下面ip是VNC服务端的地址）：
VNC Server： 112.112.113.56:5901
Encrytion：Let VNC Server choose
然后输入vncpasswd的密码即可完成VNC远程连接！
问题：Could not make bus activated clients aware of XDG_CURRENT_DESKTOP=GNOME environment variable:
Could not connect: Connection refused
[root@kevin ~]# cat /root/.vnc/kevin:1.log
...........
...........
(imsettings-check:31898): GLib-GIO-CRITICAL **: 21:56:03.842: g_dbus_proxy_call_sync_internal: assertion 'G_IS_DBUS_PROXY (proxy)' failed
GLib-GIO-Message: 21:56:03.854: Using the 'memory' GSettings backend. Your settings will not be saved or shared with other applications.
** (process:31798): WARNING **: 21:56:03.861: Could not make bus activated clients aware of XDG_CURRENT_DESKTOP=GNOME environment variable:
Could not connect: Connection refused
原因：dbus-daemon存在冲突。
因为root系统环境中装有anaconda，它的bin目录中的dbus-daemon会与系统自带的dbus-daemon冲突。
[root@kevin ~]# find / -name "dbus-daemon"
/usr/bin/dbus-daemon
/data/anaconda3/bin/dbus-daemon
/data/anaconda3/pkgs/dbus-1.13.6-h746ee38_0/bin/dbus-daemon
[root@kevin ~]# which dbus-daemon
/data/anaconda3/bin/dbus-daemon
解决办法：使用非root用户启动vncserver
[root@kevin ~]# useradd vncuser
[root@kevin ~]# echo "vncuser@123"|passwd --stdin vncuser
[root@kevin ~]# vim /etc/sudoers
vncuser ALL=(ALL) NOPASSWD: ALL
修改vncserver使用vncuser这个非root用户启动
[root@kevin ~]# cat /etc/systemd/system/vncserver@:1.service
..........
..........
ExecStart=/usr/sbin/runuser -l vncuser -c "/usr/bin/vncserver %i"
PIDFile=/root/.vnc/%H%i.pid
接着切入到非root用户vncuser下启动vncserver
[root@kevin ~]# su - vncuser
Last login: Tue Jul 2 22:05:38 CST 2019 on pts/2
设置vnc登录密码
[vncuser@kevin ~]$ vncpasswd
启动vnc
[vncuser@kevin ~]$ vncserver
查看vnc日志
[vncuser@kevin ~]$ cd .vnc/
[vncuser@kevin .vnc]$ ll
total 20
-rw-r--r-- 1 vncuser vncuser 332 Jul 2 22:06 config
-rw-rw-r-- 1 vncuser vncuser 1046 Jul 2 22:10 kevin:1.log
-rw-rw-r-- 1 vncuser vncuser 5 Jul 2 22:06 kevin:1.pid
-rw------- 1 vncuser vncuser 8 Jul 2 22:06 passwd
-rwxr-xr-x 1 vncuser vncuser 112 Jul 2 22:06 xstartup
[vncuser@kevin .vnc]$ cat kevin\:1.log
Xvnc TigerVNC 1.8.0 - built Nov 2 2018 19:05:14
Copyright (C) 1999-2017 TigerVNC Team and many others (see README.txt)
See http://www.tigervnc.org for information on TigerVNC.
Underlying X server release 12001000, The X.Org Foundation
Tue Jul 2 22:06:26 2019
vncext: VNC extension running!
vncext: Listening for VNC connections on all interface(s), port 5901
vncext: created VNC server for screen 0
touch: cannot touch ‘/home/vncuser/.cache/imsettings/log’: No such file or directory
Tue Jul 2 22:06:30 2019
ComparingUpdateTracker: 0 pixels in / 0 pixels out
ComparingUpdateTracker: (1:-nan ratio)
Tue Jul 2 22:10:22 2019
Connections: accepted: 192.168.1.200::56162
Tue Jul 2 22:10:23 2019
Connections: closed: 192.168.1.200::56162 (reading version failed: not an RFB
client?)
EncodeManager: Framebuffer updates: 0
EncodeManager: Total: 0 rects, 0 pixels
EncodeManager: 0 B (1:-nan ratio)
ComparingUpdateTracker: 0 pixels in / 0 pixels out
ComparingUpdateTracker: (1:-nan ratio)