CentOS 七安装VNC Server
本文操作流程具体参考自https://docs.oracle.com/cd/E52668_01/E54669/html/ol7-vnc-config.html
系统版本
$ uname -a
Linux localhost.localdomain 3.10.0-327.el7.x86_64 #1 SMP Thu Nov 19 22:10:57 UTC 2015 x86_64 x86_64
内核
$ cat /etc/redhat-release
CentOS Linux release 7.2.1511 (Core)
当初安装时选择的是最小化的安装模式，所以如果你已经安装了图形化界面的系统可以跳过下面的X-Window安装，直接安装VNC Server
以下命令必须以 root 权限运行，要切换到 root，或者在想要执行操作的用户添加到sudo中，那每个命令前面都要加上sudo前缀表示当前用户临时拥有像root一样的执行权限
# visudo
找到“root ALL=(ALL) ALL”，在下面添加一行：XXX ALL=(ALL) ALL，XXX为用户名
好了，废话不多说，开始安装VNC Server
1 首先需要安装X-Window
# yum check-update
# yum groupinstall "X Window System"
# yum install gnome-classic-session gnome-terminal nautilus-open-terminal control-center liberation-mono-fonts
或者直接下面一条命令
# yum groupinstall -y "GNOME Desktop"
2 安装 VNC 服务器（需要有网，如果没网的话，自己设置yum源为CD安装盘）
# yun list|grep vnc #查看yum下相关的vnc包信息
# rpm -qa|grep vnc #查看vnc是否安装
# yum install tigervnc-server -y #CentOS/RHEL 6开始版本的安装
如果是CentOS/RHEL 5，则执行下面命令
# yum install vnc-server -y
3 设置vncpasswd密码
# vncpasswd
....输入该用户的登录密码，如果执行该命令没反应的话，建议最好重装vncserver
如果设置普通用户的登录密码，请先切换到普通用户下，再执行vncpasswd进行设置
在这里要科普下vnc的相关知识点
# systemctl status vncserver@:.service
● vncserver@:.service - Remote desktop service (VNC)
Loaded: loaded (/usr/lib/systemd/system/vncserver@.service; disabled; vendor preset: disabled)
Active: inactive (dead)
# systemctl is-enabled vncserver@.service
disabled
为什么会是不可使用呢?这是因为每个用户在VNC守护服务线程下，都是一个独立的实例；另一方面，VNC不能只运行一个单线程来处理每一个用户请求。
每一个用户连接到VNC时，VNC都会启动一个新的守护实例。CentOS 7使用systemd守护线程来初始化其他服务。每一个通过yum安装的服务都是运行在systemd下，并且各自的服务单元模块文件都存放于/lib/systemd/system目录下。
在/etc/systemd/system/目录下存放着一个跟相关服务的链接，在boot启动时，可以自动地根据链接来启动线程。
所以在这个案例中，你可以使用下面的命令看到该文件
# ls -l /lib/systemd/system/vnc*
-rw-r--r--. 1 root root 1738 Apr 1 2016 /lib/systemd/system/vncserver@.service
# ls -l /etc/systemd/system/*.wants/vnc*
ls: cannot access /etc/systemd/system/*.wants/vnc.*: No such file ore direcotry
所以可以直接复制vncserver@.service文件来作为各自实例的配置文件
参考自https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-vnc-remote-access-for-the-gnome-desktop-on-centos-7
4 创建VNC配置文件
正常安装好vncserver后，该文件/lib/systemd/system/vncserver@.service是有内容的，如果该文件的内容为空，建议重装vncserver，减少不必要的麻烦
这里的vncserver@:1.service为root用户的登录配置文件，vncserver@:2.service为普通用户的配置文件
# cp /lib/systemd/system/vncserver@.service \
/etc/systemd/system/vncserver@:1.service
# cp /lib/systemd/system/vncserver@.service \
/etc/systemd/system/vncserver@:2.service
# vi /etc/systemd/vncserver@:1.service
# The vncserver service unit file
#
# Quick HowTo:
# 1. Copy this file to /etc/systemd/system/vncserver@.service
# 2. Edit <USER> and vncserver parameters appropriately
# ("runuser -l <USER> -c /usr/bin/vncserver %i -arg1 -arg2")
# 3. Run `systemctl daemon-reload`
# 4. Run `systemctl enable vncserver@:<display>.service`
#
# DO NOT RUN THIS SERVICE if your local area network is
# untrusted! For a secure way of using VNC, you should
# limit connections to the local host and then tunnel from
# the machine you want to view VNC on (host A) to the machine
# whose VNC output you want to view (host B)
#
# [user@hostA ~]$ ssh -v -C -L 590N:localhost:590M hostB
#
# this will open a connection on port 590N of your hostA to hostB's port 590M
# (in fact, it ssh-connects to hostB and then connects to localhost (on hostB).
# See the ssh man page for details on port forwarding)
#
# You can then point a VNC client on hostA at vncdisplay N of localhost and with
# the help of ssh, you end up seeing what hostB makes available on port 590M
#
# Use "-nolisten tcp" to prevent X connections to your VNC server via TCP.
#
# Use "-localhost" to prevent remote VNC clients connecting except when
# doing so through a secure tunnel. See the "-via" option in the
# `man vncviewer' manual page.
[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 <USER> -c "/usr/bin/vncserver %i"
PIDFile=/home/<USER>/.vnc/%H%i.pid
ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
[Install]
WantedBy=multi-user.target
修改上面红色字体为用户名和所在的家目录即可，然后保存，执行下面命令使其生效
# systemctl daemon-reload
5 启动VNCServer服务
# systemctl start vncserver@\:1.service
Job for vncserver@:1.service failed because the control process exited with error code. See "systemctl status vncserver@:1.service" and "journalctl -xe" for details.
出现错误，按照错误提示，执行下面命令
# systemctl status vncserver@\:1.service
● vncserver@:1.service - Remote desktop service (VNC)
Loaded: loaded (/etc/systemd/system/vncserver@:1.service; disabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Mon 2016-11-21 20:34:40 CST; 1min 32s ago
Process: 11295 ExecStart=/usr/sbin/runuser -l root -c /usr/bin/vncserver %i (code=exited, status=1/FAILURE)
Process: 11292 ExecStartPre=/bin/sh -c /usr/bin/vncserver -kill %i > /dev/null 2>&1 || : (code=exited, status=0/SUCCESS)
Nov 21 20:34:39 localhost.localdomain systemd[1]: Starting Remote desktop service (VNC)...
Nov 21 20:34:40 localhost.localdomain runuser[11295]: Password:
Nov 21 20:34:40 localhost.localdomain systemd[1]: vncserver@:1.service: control process exited, code=exited status=1
Nov 21 20:34:40 localhost.localdomain systemd[1]: Failed to start Remote desktop service (VNC).
Nov 21 20:34:40 localhost.localdomain systemd[1]: Unit vncserver@:1.service entered failed state.
Nov 21 20:34:40 localhost.localdomain systemd[1]: vncserver@:1.service failed.
看到上面的错误提示，注意到好像还没设置root用户的vncpasswd密码!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
# vncspasswd #设置root的vncpasswd密码
# su XXX
$ vncpasswd #设置XXX的vncpasswd密码
# systemctl start vncserver@\:1.service #启动vnc服务
# systemctl stop vncserver@\:1.service #关闭vnc服务
# systemctl status vncserver@\:1.service
● vncserver@:1.service - Remote desktop service (VNC)
Loaded: loaded (/etc/systemd/system/vncserver@:1.service; disabled; vendor preset: disabled)
Active: active (running) since Mon 2016-11-21 20:38:42 CST; 1min 55s ago
Process: 11346 ExecStart=/usr/sbin/runuser -l root -c /usr/bin/vncserver %i (code=exited, status=0/SUCCESS)
Process: 11343 ExecStartPre=/bin/sh -c /usr/bin/vncserver -kill %i > /dev/null 2>&1 || : (code=exited, status=0/SUCCESS)
Main PID: 11367 (Xvnc)
CGroup: /system.slice/system-vncserver.slice/vncserver@:1.service
‣ 11367 /usr/bin/Xvnc :1 -desktop localhost.localdomain:1 (root) -auth /root/.Xauthority -geometry 1024x7...
Nov 21 20:38:39 localhost.localdomain systemd[1]: Starting Remote desktop service (VNC)...
Nov 21 20:38:42 localhost.localdomain systemd[1]: Started Remote desktop service (VNC).
看到这种提示并显示active(running)说明vncserver启动成功了
# systemctl enable vncserver@:1.service #设置开机自启动
Created symlink from /etc/systemd/system/multi-user.target.wants/vncserver@:1.service to /etc/systemd/system/vncserver@:1.service.
# systemctl disable vncserver@:1.service #取消开机自启动
Removed symlink /etc/systemd/system/multi-user.target.wants/vncserver@:1.service.
注：如果有修改配置文件，都必须重新加载配置和重启服务
# systemctl daemon-reload
# systemctl restart vncserver@:1.service
6 配置防火墙
centos从7开始默认用的是firewalld，这个是基于iptables的，虽然有iptables的核心，但是iptables的服务是没安装的
# firewall-cmd --state #查看防火墙的启动状态
running
# systemctl start firewalld #如果没启动防火墙的话则启动，为了网络安全
# firewall-cmd --zone=public --add-service=vnc-server --permanent #永久的把vnc-server服务加进防火墙
# firewall-cmd --zone=public --list-services
# firewall-cmd --zone=public --add-port=5901-5902/tcp --permanent #永久的把该端口添加进防火墙
success
# firewall-cmd --zone=public --list-ports #查看开放的端口有哪些
# firewall-cmd --reload #重启防火墙，让刚才的设置生效
7 配置VNC桌面(根据自己的偏好设置启动什么GUI)[可选]
# vi ~/.vnc/xstartup
在末尾添加
startkde &
设置成链接时启动kde
# systemctl restart vncserver@\:1.service
8 在Windows下，安装VNC Viewer，输入正确IP地址、窗口号和密码，即可远程
或者使用SSH通道的客户端程序,如：PuTTY
参考自https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-vnc-remote-access-for-the-gnome-desktop-on-centos-7
在使用的过程中，VNC界面有时会没有反应，这时应该如何操作呢
通过SSH登录系统，然后通过命令重启自己的VNC Server
$ ls ~/.vnc/ #查看自己的端口号是多少
$ vncserver -kill :2 #结束VNC服务及远程桌面
$ vncserver :2 -geometry 1280x760
此时通过VNC Viewer登录试试，应该可以了
注意:vncserver只能由启动它的用户来关闭，即时是root也不能关闭其它用户开启的vncserver，除非用kill命令杀死进程
在安装的过程中，一开始用yum安装时显示complete，但在进行配置时发现配置文件是空，按照网上说的各种教程来设置时，也都出现各种其他问题，这时就要考虑是否卸载掉然后重新装过了，在该过程中遇到的错误有：
# /bin/systemctl start vncserver.service#启动vncserver服务
出现:
Failed to start vncserver.service: Unit vncserver.service failed to load: No such file or directory.
# systemctl enable vncserver.service
出现:
Failed to execute operation: Access denied
# service vncserver status
Redirecting to /bin/systemctl status vncserver.service
● vncserver.service
Loaded: not-found (Reason: No such file or directory)
Active: inactive (dead)
# systemctl status vncserver@:.service
● vncserver@:.service
Loaded: masked (/usr/lib/systemd/system/vncserver@.service; masked; vendor preset: disabled)
Active: inactive (dead)
# systemctl is-enabled vncserver@.service
masked
# systemctl enable vncserver@:1.service
The unit files have no [Install] section. They are not meant to be enabled
using systemctl.
Possible reasons for having this kind of units are:
1) A unit may be statically enabled by being symlinked from another unit's
.wants/ or .requires/ directory.
2) A unit's purpose may be to act as a helper for some other unit which has
a requirement dependency on it.
3) A unit may be started when needed via activation (socket, path, timer,
D-Bus, udev, scripted systemctl call, ...).
http://lists.opensuse.org/opensuse-bugs/2013-11/msg04269.html
Mailinglist Archive: opensuse-bugs (5295 mails)
# 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.
# systemctl -l status vncserver@:1.service
● vncserver@:1.service - Remote desktop service (VNC)
Loaded: loaded (/etc/systemd/system/vncserver@:1.service; static; vendor preset: disabled)
Active: failed (Result: resources) since Mon 2016-11-21 18:49:42 CST; 12min ago
Process: 9809 ExecStart=/sbin/runuser -l root -c /usr/bin/vncserver %i -geometry 1280x760 (code=exited, status=0/SUCCESS)
Process: 9804 ExecStartPre=/bin/sh -c /usr/bin/vncserver -kill %i > /dev/null 2>&1 || : (code=exited, status=0/SUCCESS)
Nov 21 18:49:42 localhost.localdomain systemd[1]: Starting Remote desktop service (VNC)...
Nov 21 18:49:42 localhost.localdomain systemd[1]: PID file /root/.vnc/localhost.localdomain:1,pid not readable (yet?) after start.
Nov 21 18:49:42 localhost.localdomain systemd[1]: Failed to start Remote desktop service (VNC).
Nov 21 18:49:42 localhost.localdomain systemd[1]: Unit vncserver@:1.service entered failed state.
Nov 21 18:49:42 localhost.localdomain systemd[1]: vncserver@:1.service failed.
# systemctl -l status vncserver@:1.service
● vncserver@:1.service - Remote desktop service (VNC)
Loaded: loaded (/etc/systemd/system/vncserver@:1.service; disabled; vendor preset: disabled)
Active: failed (Result: resources) since Mon 2016-11-21 18:49:42 CST; 40min ago
Nov 21 18:49:42 localhost.localdomain systemd[1]: vncserver@:1.service failed.
Nov 21 19:15:55 localhost.localdomain systemd[1]: [/etc/systemd/system/vncserver@:1.service:11] Unknown lvalue 'ExectStop' in section 'Service'
Nov 21 19:15:55 localhost.localdomain systemd[1]: [/etc/systemd/system/vncserver@:1.service:13] Unknown section 'install'. Ignoring.
Nov 21 19:20:35 localhost.localdomain systemd[1]: [/etc/systemd/system/vncserver@:1.service:11] Unknown lvalue 'ExectStop' in section 'Service'
Nov 21 19:20:35 localhost.localdomain systemd[1]: [/etc/systemd/system/vncserver@:1.service:13] Unknown section 'install'. Ignoring.
Nov 21 19:20:45 localhost.localdomain systemd[1]: [/etc/systemd/system/vncserver@:1.service:11] Unknown lvalue 'ExectStop' in section 'Service'
Nov 21 19:20:45 localhost.localdomain systemd[1]: [/etc/systemd/system/vncserver@:1.service:13] Unknown section 'install'. Ignoring.
Nov 21 19:21:10 localhost.localdomain systemd[1]: Stopped Remote desktop service (VNC).
Nov 21 19:21:22 localhost.localdomain systemd[1]: [/etc/systemd/system/vncserver@:1.service:11] Unknown lvalue 'ExectStop' in section 'Service'
Nov 21 19:21:22 localhost.localdomain systemd[1]: [/etc/systemd/system/vncserver@:1.service:13] Unknown section 'install'. Ignoring.
Warning: vncserver@:1.service changed on disk. Run 'systemctl daemon-reload' to reload units.
# journalctl -xe|grep vncserver
...
-- Subject: Unit vncserver@:1.service has begun start-up
-- Unit vncserver@:1.service has begun starting up.
-- Subject: Unit vncserver@:1.service has failed
-- Unit vncserver@:1.service has failed.
Nov 21 19:32:48 localhost.localdomain systemd[1]: Unit vncserver@:1.service entered failed state.
Nov 21 19:32:48 localhost.localdomain systemd[1]: vncserver@:1.service failed.
# systemctl -l status vncserver@:1.service
● vncserver@:1.service - Remote desktop service (VNC)
Loaded: loaded (/etc/systemd/system/vncserver@:1.service; disabled; vendor preset: disabled)
Active: failed (Result: resources) since Mon 2016-11-21 19:32:48 CST; 10min ago
Nov 21 19:32:47 localhost.localdomain systemd[1]: Starting Remote desktop service (VNC)...
Nov 21 19:32:48 localhost.localdomain systemd[1]: PID file /root/.vnc/localhost.localdomain:1,pid not readable (yet?) after start.
Nov 21 19:32:48 localhost.localdomain systemd[1]: Failed to start Remote desktop service (VNC).
Nov 21 19:32:48 localhost.localdomain systemd[1]: Unit vncserver@:1.service entered failed state.
Nov 21 19:32:48 localhost.localdomain systemd[1]: vncserver@:1.service failed.
# systemctl -l 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 Mon 2016-11-21 20:12:15 CST; 57s ago
Process: 10931 ExecStart=/sbin/runuser -l root -c /usr/bin/vncserver %i (code=exited, status=0/SUCCESS)
Process: 10926 ExecStartPre=/bin/sh -c /usr/bin/vncserver -kill %i > /dev/null 2>&1 || : (code=exited, status=0/SUCCESS)
Nov 21 20:12:15 localhost.localdomain systemd[1]: Starting Remote desktop service (VNC)...
Nov 21 20:12:15 localhost.localdomain systemd[1]: PID file /root/.vnc/localhost.localdomain:1.pid not readable (yet?) after start.
Nov 21 20:12:15 localhost.localdomain systemd[1]: Failed to start Remote desktop service (VNC).
Nov 21 20:12:15 localhost.localdomain systemd[1]: Unit vncserver@:1.service entered failed state.
Nov 21 20:12:15 localhost.localdomain systemd[1]: vncserver@:1.service failed.
# journalctl -xn|grep vncserver #这个可以查看具体是什么错误信息
# netstat -tulnp #查看vncserver启动状况
在设置的过程中要多看看错误信息，这样才能更好的对症下药，更快的解决问题
载掉vncserver
# yum erase tigervnc*
# rpm -qa|grep vnc #检查是否卸载掉
以上就是小弟我在安装VNC Server碰到的各种错误，不过最终还是靠自己努力搞定了，真的发自内心的开心~~~~，上面的见解纯属个人所见，如有不足之处，望指正，谢谢 :-）