[CentOS7] 使用Xmanager連接CentOS7－片刻、瞬間、不知所云...

CentOS6和CentOS7的時候，很多指令和環境都很不一樣了，所以設定方式完全不同。

在CentOS7中，gnome的介面會有問題，因此需要改用xfce。

[root@centos7 ~]# yum install -y epel-release
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: ftp.tc.edu.tw
* extras: ftp.tc.edu.tw
.................

Installed:
epel-release.noarch 0:7-6

Complete!
[root@centos7 ~]# yum install -y lightdm && yum groupinstall -y xfce
Loaded plugins: fastestmirror, langpacks
epel/x86_64/metalink                          | 5.2 kB     00:00
epel                                                     | 4.3 kB     00:00
(1/3): epel/x86_64/group_gz               | 170 kB   00:00
.....................................

Complete!
[root@centos7 ~]# vi /etc/lightdm/lightdm.conf

................
[XDMCPServer]
Enable=true
Port=177
.............
存檔退出。

[root@centos7 ~]# systemctl disable gdm && systemctl enable lightdm
Removed symlink /etc/systemd/system/display-manager.service.
Created symlink from /etc/systemd/system/display-manager.service to /usr/lib/systemd/system/lightdm.service.
[root@centos7 ~]# systemctl start lightdm    //啟動lightdm
[root@centos7 ~]# systemctl stop firewalld.service     //關閉防火牆
[root@centos7 ~]# systemctl status lightdm      //檢查lightdm的狀態是否正確。
● lightdm.service - Light Display Manager
   Loaded: loaded (/usr/lib/systemd/system/lightdm.service; enabled; vendor preset: enabled)
   Active: active (running) since 二 2016-09-06 16:12:30 CST; 57s ago
     Docs: man:lightdm(1)
Main PID: 8248 (lightdm)
   CGroup: /system.slice/lightdm.service
           ├─8248 /usr/sbin/lightdm
           ├─8256 /usr/bin/X -background none :1 -seat seat0 -auth /var/run/l...
           └─8309 lightdm --session-child 14 21

9月 06 16:12:30 centos7.vb systemd[1]: Starting Light Display Manager...
9月 06 16:12:30 centos7.vb systemd[1]: Started Light Display Manager.
9月 06 16:12:30 centos7.vb lightdm[8272]: pam_unix(lightdm-greeter:session...)
Hint: Some lines were ellipsized, use -l to show in full.

(原則上上面的顯示表示正常，但萬一有錯誤，請把xsessions下的gnome的設定檔都刪除，強迫系統抓xfce)

[root@centos7 ~]# cd /usr/share/xsessions/
[root@centos7 xsessions]# ls
gnome-classic.desktop gnome.desktop
gnome-custom-session.desktop xfce.desktop
[root@centos7 xsessions]# mkdir old
[root@centos7 xsessions]# mv gnome* old
[root@centos7 xsessions]# ls
old xfce.desktop
[root@centos7 xsessions]# init 3 && init 5 //重新啟動desktop，或是reboot也可以。
PolicyKit daemon disconnected from the bus.
We are no longer a registered authentication agent.
PolicyKit daemon disconnected from the bus.
We are no longer a registered authentication agent.
PolicyKit daemon reconnected to bus.
Attempting to re-register as an authentication agent.
We are now a registered authentication agent.