CentOS 7.x 命令行下安装图形化界面

1. 安装组件包，时间略长，请耐心等待。

  0 16:36:25 root@cytemp,172.16.15.2:~ # yum -y groupinstall "GNOME Desktop" "Graphical Administration Tools"

2. 修改系统默认启动方式。

# 默认是启动命令行界面。
  0 16:42:23 root@cytemp,172.16.15.2:~ # ll /etc/systemd/system/default.target
lrwxrwxrwx. 1 root root 37 2月  25 02:11 /etc/systemd/system/default.target -> /lib/systemd/system/multi-user.target
# 修改为默认启动图形化界面。
  0 16:45:25 root@cytemp,172.16.15.2:~ # ln -sf /lib/systemd/system/runlevel5.target /etc/systemd/system/default.target
  0 16:58:56 root@cytemp,172.16.15.2:~ # shutdown -r now

3. 扩展：安装vncserver。

  0 17:03:39 root@cytemp,172.16.15.2:~ # yum -y install tigervnc-server
  0 17:03:57 root@cytemp,172.16.15.2:~ # cd /etc/systemd/system
  0 17:04:02 root@cytemp,172.16.15.2:/etc/systemd/system # cp /lib/systemd/system/vncserver@.service ./vncserver@:1.service
  0 17:04:43 root@cytemp,172.16.15.2:/etc/systemd/system # vim vncserver@\:1.service
[Unit]
Description=Remote desktop service (VNC)
After=syslog.target network.target

[Service]
Type=simple

# Clean any existing files in /tmp/.X11-unix environment
ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
ExecStart=/usr/bin/vncserver_wrapper root %i
ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'

[Install]
WantedBy=multi-user.target
# 需要先设置VNC密码才能启动，普通用户需要切到普通用户下才能设置VNC密码。
  0 17:06:59 root@cytemp,172.16.15.2:/etc/systemd/system # vncpasswd
Password:
Verify:
Would you like to enter a view-only password (y/n)? n
  0 17:06:00 root@cytemp,172.16.15.2:/etc/systemd/system # systemctl daemon-reload
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# 如果显示不全面则需要修改分辨率
vim /usr/bin/vncserver
$geometry = "2560x1440";    # 修改为实际显示器分辨率即可
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  0 17:07:19 root@cytemp,172.16.15.2:/etc/systemd/system # systemctl start vncserver@:1.service
# VNC默认以5901为第一个端口，多用户使用时，端口顺序分配。
  0 17:07:20 root@cytemp,172.16.15.2:/etc/systemd/system # ps -ef | grep -i vnc
root      8255     1  0 17:07 ?        00:00:00 /bin/sh /usr/bin/vncserver_wrapper root :1
root      8295     1  0 17:07 ?        00:00:00 /usr/bin/Xvnc :1 -auth /root/.Xauthority -desktop trainee2:1 (root) -fp catalogue:/etc/X11/fontpath.d -geometry 2560x1440 -pn -rfbauth /root/.vnc/passwd -rfbport 5901 -rfbwait 30000
root      8319     1  0 17:07 ?        00:00:00 /bin/sh /root/.vnc/xstartup
root      9134  2214  0 17:07 pts/0    00:00:00 grep --color=auto vnc
# 多用户使用VNC
  0 17:07:22 root@cytemp,172.16.15.2:/etc/systemd/system # cp vncserver@\:1.service vncserver@\:2.service
  0 17:10:34 root@cytemp,172.16.15.2:/etc/systemd/system # sed -i 's/root/liuhuan/g' vncserver@\:2.service
  0 17:10:49 root@cytemp,172.16.15.2:/etc/systemd/system # su - liuhuan 
上一次登录：四 4月 15 15:04:01 CST 2021从 101.228.245.134pts/4 上
  0 17:11:09 liuhuan@cytemp,172.16.15.2:~ $ vncpasswd 
  0 17:11:26 liuhuan@cytemp,172.16.15.2:~ $ 登出
  0 17:11:27 root@cytemp,172.16.15.2:/etc/systemd/system # systemctl daemon-reload 
  0 17:12:37 root@cytemp,172.16.15.2:/etc/systemd/system # systemctl start vncserver@\:2.service
# 有防火墙的话，将对应启动的端口开放出去（比如上例将liuhuan的5902端口开放），就可以使用VNC连接了。

写作不易，转载请注明出处，谢谢~~