[oracle@localhost database]$ ./runInstaller

Starting Oracle Universal Installer...

 Checking Temp space: must be greater than 120 MB.   Actual 38232 MB    Passed

Checking swap space: must be greater than 150 MB.   Actual 3999 MB    Passed

Checking monitor: must be configured to display at least 256colors

    >>> Could notexecute auto check for display colors using command /usr/bin/xdpyinfo. Check ifthe DISPLAY variable is set.    Failed<<<<

 Some requirement checks failed. You must fulfill theserequirements before

 continuing with the installation,

 Continue? (y/n) [n]

解决方法：

[root@localhost Packages]# xhost +
xhost:  unable to open display "192.168.56.144:0.0"
[root@localhost Packages]# export DISPLAY=:0.0
[root@localhost Packages]# xhost +
access control disabled, clients can connect from any host
[root@localhost Packages]# xclock

出现小钟就ok了。