[SOLVED] Bit confused about display env variable settings in RHEL5

thiyagusham · 04-04-2013, 03:01 PM

Hello to all ;

I need small clarification for display env variable ..
I got error when setting display variable

PHP Code:



[root@rhel5 ~]# hostname
rhel5.linuxserver

[root@rhel5 ~]# xhost +
access control disabled, clients can connect from any host

[root@rhel5 ~]# su - oracle
[oracle@rhel5 ~]$ DISPLAY=local_host:0.0 ;  export DISPLAY

PHP Code:



[oracle@rhel5 ~]$ cd /u01/
[oracle@rhel5 u01]$ ./runInstaller 

Starting Oracle Universal Installer...
Checking installer requirements...
Checking operating system version: must be redhat-3, SuSE-9, redhat-4, UnitedLinux-1.0, asianux-1 or asianux-2
                                      Passed
All installer requirements met.
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2013-04-04_08-12-54PM. Please wait ...
[oracle@rhel5 u01]$ Exception in thread "main"
java.lang.InternalError: Can't connect to X11 window server using 'localhost:0.0' as the value of the DISPLAY variable.

>> I did n't get an error when refusing to set display env variable >>

PHP Code:



[root@rhel5 ~]# hostname
rhel5.linuxserver

[root@rhel5 ~]# xhost +
access control disabled, clients can connect from any host

[root@rhel5 ~]# su - oracle
[oracle@rhel5 ~]$ DISPLAY=:0.0 ;  export DISPLAY

Here , i got OUI Screen

> but getting bit confused and don't understand what actually happend in both scanarios ..

Please review attached screenshot and kindly please explain it !

Thanks in advance ..

eSelix · 04-04-2013, 06:27 PM

Change "local_host" to "localhost". Or it is defined somewhere?

thiyagusham · 04-04-2013, 06:32 PM

Hi ; i need lit bit explanation regarding this .. I am getting confused .. please clarify ..

chrism01 · 04-04-2013, 06:33 PM

1. As above, try localhost, not local_host.

2. I note it says it must be RHEL3 or RHEL4, but you're doing this on RHEL5?
Is this really the correct version to install...?

thiyagusham · 04-04-2013, 06:43 PM

Thanks Chrism01

I note it says it must be RHEL3 or RHEL4, but you're doing this on RHEL5?

Yes obviously rhel5.

As per supporting doc , need to change version from rhel-5 to rhel-4

Replace the release Information (RedHat Enterprise Linux Server release 5 (Tikanga)) to redhat -4.

Is this really the correct version to install...?

Yes ..

chrism01 · 04-04-2013, 08:07 PM

I think you didn't get my point; you shouldn't install that version on RHEL5. It might(!) work, but you'd be better off getting the version designed to be installed on RHEL5.
Don't backtrack to RHEL4; its out of (normal) support at RH http://www.redhat.com/security/updates/errata/

thiyagusham · 04-04-2013, 09:01 PM

Hi Chrismo1 ;

Thanks for your clarification ..

thiyagusham · 04-04-2013, 09:07 PM

Finally one more question

Is this compulsory ?

Should we set display variable every time i.e( Installation ) ?

because i issued echo $DISPALY command ( before setting display variable) it showed :0.0

then what's the need to set once again ?

Thanks Chrism01.

chrism01 · 04-05-2013, 02:03 AM

I'd stick to whatever the instructions say; probably set it every time.
Never assume (you know what they say about 'assume' ..

)

jpollard · 04-05-2013, 08:01 AM

Note: By default most systems disable the TCP connection to the X server.
Instead, use ssh to forward connections (more secure).

The normal default for X is to use UNIX domain sockets rather than TCP.

using xhost + disables access controls - which means anyone on your network
can connect and capture your display, and keystrokes.

That means they can capture any passwords you use.