如果在安装过程中忘记安装图形界面，后期可以在命令行下面进行安装。
先把安装光盘mount到系统中。
如果安装映像mount到/mnt/DVD目录下
[ncapp@nrb-ncapp-p01 ~]$ mount -l
/dev/mapper/vg_nrbncappp01-LogVol00 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
/dev/sda1 on /boot type ext4 (rw)
/dev/mapper/vg_nrbncappp01-LogVol02 on /home type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/sr0 on /media/RHEL-6.8 Server.x86_64 type iso9660 (ro,nosuid,nodev,uhelper=udisks,uid=0,gid=0,iocharset=utf8,mode=0400,dmode=0500) [RHEL-6.8 Server.x86_64]
/dev/sr0 on /mnt/DVD type iso9660 (ro) [RHEL-6.8 Server.x86_64]本文主要是通过yum安装，所以需要修收配置文件, 通过vi /etc/yum.repos.d/rhel-source.repo,增加红色部分代码。
[ncapp@nrb-ncapp-p01 etc]$ cd yum.repos.d/
[ncapp@nrb-ncapp-p01 yum.repos.d]$ ls
packagekit-media.repo redhat.repo rhel-source.repo
[ncapp@nrb-ncapp-p01 yum.repos.d]$ cat rhel-source.repo
[local]
name=local
baseurl=file:///mnt/DVD
enabled=1
gpgcheck=0
[rhel-source]
name=Red Hat Enterprise Linux $releasever - $basearch - Source
baseurl=ftp://ftp.redhat.com/pub/redhat/linux/enterprise/$releasever/en/os/SRPMS/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release[rhel-source-beta]
name=Red Hat Enterprise Linux $releasever Beta - $basearch - Source
baseurl=ftp://ftp.redhat.com/pub/redhat/linux/beta/$releasever/en/os/SRPMS/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-beta,file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
[ncapp@nrb-ncapp-p01 yum.repos.d]$查看已安装的包，和可安装的包，图形界面主要与这两个包有关系，主要与以下标记红色的包有关系，可以通过 yum groupinstall "X Windows system", yum groupinstall "Desktop" 分别安装这两个包
[ncapp@nrb-ncapp-p01 yum.repos.d]$ yum grouplist
Loaded plugins: product-id, refresh-packagekit, search-disabled-repos, security, subscription-
: manager
Setting up Group Process
Installed Groups:
Additional Development
Base
Compatibility libraries
Console internet tools
Debugging Tools
Desktop
Desktop Debugging and Performance Tools
Desktop Platform
Dial-up Networking Support
Directory Client
E-mail server
Fonts
General Purpose Desktop
Graphical Administration Tools
Hardware monitoring utilities
Input Methods
Java Platform
Large Systems Performance
Legacy UNIX compatibility
Legacy X Window System compatibility
NFS file server
Network Infrastructure Server
Network file system client
Networking Tools
Performance Tools
Perl Support
Scientific support
Security Tools
Server Platform
X Window System
Installed Language Groups:
Arabic Support [ar]
Armenian Support [hy]
Chinese Support [zh]
Georgian Support [ka]
Hebrew Support [he]
Inuktitut Support [iu]
Japanese Support [ja]
Korean Support [ko]
Lao Support [lo]
Tajik Support [tg]
Available Groups:
Backup Client
Backup Server
CIFS file server
Client management tools
Desktop Platform Development
Development tools
Directory Server
Eclipse
Emacs
FCoE Storage Client
FTP server
Graphics Creation Tools
Guest Agents
Identity Management Server
Infiniband Support
Internet Browser
KDE Desktop
Mainframe Access
Messaging Client Support
MySQL Database client
MySQL Database server
Network Storage Server
PHP Support
PostgreSQL Database client
PostgreSQL Database server
Print Server
Printing client
Remote Desktop Clients
Ruby Support
SNMP Support
Server Platform Development
Smart card support
Storage Availability Tools
System Management
System administration tools
TeX support
Technical Writing
TurboGears application framework
Virtualization
Virtualization Client
Virtualization Platform
Virtualization Tools
Web Server
Web Servlet Engine
Web-Based Enterprise Management
iSCSI Storage Client
Available Language Groups:
Afrikaans Support [af]
Albanian Support [sq]
Amazigh Support [ber]
Assamese Support [as]
Azerbaijani Support [az]
Basque Support [eu]
Belarusian Support [be]
Bengali Support [bn]
Bhutanese Support [dz]
Brazilian Portuguese Support [pt_BR]
Breton Support [br]
Bulgarian Support [bg]
Catalan Support [ca]
Chhattisgarhi Support [hne]
Chichewa Support [ny]
Coptic Support [cop]
Croatian Support [hr]
Czech Support [cs]
Danish Support [da]
Dutch Support [nl]
English (UK) Support [en_GB]
Esperanto Support [eo]
Estonian Support [et]
Ethiopic Support [am]
Faroese Support [fo]
Fijian Support [fj]
Filipino Support [fil]
Finnish Support [fi]
French Support [fr]
Frisian Support [fy]
Friulian Support [fur]
Gaelic Support [gd]
Galician Support [gl]
German Support [de]
Greek Support [el]
Gujarati Support [gu]
Hiligaynon Support [hil]
Hindi Support [hi]
Hungarian Support [hu]
Icelandic Support [is]
Indonesian Support [id]
Interlingua Support [ia]
Irish Support [ga]
Italian Support [it]
Kannada Support [kn]
Kashmiri Support [ks]
Kashubian Support [csb]
Kazakh Support [kk]
Khmer Support [km]
Kinyarwanda Support [rw]
Konkani Support [kok]
Kurdish Support [ku]
Latin Support [la]
Latvian Support [lv]
Lithuanian Support [lt]
Low Saxon Support [nds]
Luxembourgish Support [lb]
Macedonian Support [mk]
Maithili Support [mai]
Malagasy Support [mg]
Malay Support [ms]
Malayalam Support [ml]
Maltese Support [mt]
Manx Support [gv]
Maori Support [mi]
Marathi Support [mr]
Mongolian Support [mn]
Myanmar (Burmese) Support [my]
Nepali Support [ne]
Northern Sotho Support [nso]
Norwegian Support [nb]
Occitan Support [oc]
Oriya Support [or]
Persian Support [fa]
Polish Support [pl]
Portuguese Support [pt]
Punjabi Support [pa]
Romanian Support [ro]
Russian Support [ru]
Sanskrit Support [sa]
Sardinian Support [sc]
Serbian Support [sr]
Sindhi Support [sd]
Sinhala Support [si]
Slovak Support [sk]
Slovenian Support [sl]
Somali Support [so]
Southern Ndebele Support [nr]
Southern Sotho Support [st]
Spanish Support [es]
Swahili Support [sw]
Swati Support [ss]
Swedish Support [sv]
Tagalog Support [tl]
Tamil Support [ta]
Telugu Support [te]
Tetum Support [tet]
Thai Support [th]
Tibetan Support [bo]
Tsonga Support [ts]
Tswana Support [tn]
Turkish Support [tr]
Turkmen Support [tk]
Ukrainian Support [uk]
Upper Sorbian Support [hsb]
Urdu Support [ur]
Uzbek Support [uz]
Venda Support [ve]
Vietnamese Support [vi]
Walloon Support [wa]
Welsh Support [cy]
Xhosa Support [xh]
Zulu Support [zu]
Done安装到这里就可以启动"startX",但是linux不建议有root直接登陆图形界面，我们可以新建一个普通用户。
[ncapp@nrb-ncapp-p01 yum.repos.d] useradd xxx
[ncapp@nrb-ncapp-p01 yum.repos.d]passwd xxx
至此，已经可以通过新建的用户使用startx进入图形界面了，但是如果这时重启的话还是会进行命令行界面，所以需要调整开机进行桌面还是命令界面。
[root@redhat ~]#vim /etc/inittab
# System initialization is started by /etc/init/rcS.conf
#
# Individual runlevels are started by /etc/init/rc.conf
#
# Ctrl-Alt-Delete is handled by /etc/init/control-alt-delete.conf
#
# Terminal gettys are handled by /etc/init/tty.conf and /etc/init/serial.conf,
# with configuration in /etc/sysconfig/init.
#
# For information on how to write upstart event handlers, or how
# upstart works, see init(5), init(8), and initctl(8).
#
# Default runlevel. The runlevels used are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
#
id:3:initdefault:
将上面红字部分的 3改成53为命令行界面 5为X window图形界面
删除redhat订阅：
rhel6.1新增了一个redhat订阅，没有用，可以删除[root@redhat ~]# yum remove subscription*
安装桌面右键终端：
[root@redhat ~]# yum install nautilus-open-terminal