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CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/09 20:38:23
by aceofblackstar
Hello

I have minor problem. I am used to windows and netware environments. New to CentOS.

How do I remotely access the server for administration with a Graphical interface similar to Remote desktop in windows..
"Start-> Run -> MSTSC"

:-)

Thank You......
Ace

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/09 20:44:57
by pschaff
Depends on what you're running on the desktop. I'm guessing you mean that the desktop system will be Windows. Either way there are two primary options:
1. Run an X server and Secure Shell (ssh) client and display the apps on the desktop. Xming, PuTTY, and Cygwin are some windows applications.
2. Run a VNC server on the CentOS server and a VNC client on the desktop. See http://wiki.centos.org/HowTos/VNC-Server

Option 1 would be a lot easier if the desktop were Linux also as everything you need would already be installed, or at worst a "yum install" away. Actually the same can be said for option 2, but it requires somewhat more configuration on the server end.

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/10 17:18:22
by aceofblackstar
Thanks

Will Try this...

:-)

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/10 19:46:46
by aceofblackstar
I followed these steps.... with different username and password.... but I cannot access it through url or vnc client.... I can ping from these machines and access nagios which I am running from these windows machines.... tried it with IE7 and Firefox......

Is there additonal steps I have to take:

==============================================================

http://wiki.centos.org/HowTos/VNC-Server




2. Configuring un-encrypted VNC

We will be setting up VNC for 3 users. These will be 'larry', 'moe', and 'curly'.

You will perform the following steps to configure your VNC server:

1. Create your VNC users.
2. Set your users' VNC passwords.
3. Edit the server configuration.
4. Create and customize xstartup scripts.
5. Start the VNC service.
6. Test each VNC user.
7. Setup the VNC service to start on reboot.
8. Additional optional enhancements

2.1. Create your VNC users

As root:

# useradd larry
# useradd moe
# useradd curly
# passwd larry
# passwd moe
# passwd curly

2.2. Set your users' VNC passwords

Login to each user, and run vncpasswd. This will create a .vnc directory.

[~]$ cd .vnc
[.vnc]$ ls
passwd

2.3. Edit the server configuration

Edit /etc/sysconfig/vncservers, and add the following to the end of the file.

VNCSERVERS="1:larry 2:moe 3:curly"
VNCSERVERARGS[1]="-geometry 640x480"
VNCSERVERARGS[2]="-geometry 640x480"
VNCSERVERARGS[3]="-geometry 800x600"

Larry will have a 640 by 480 screen, as will moe. Curly will have an 800 by 600 screen.

2.4. Create xstartup scripts

We will create the xstartup scripts by starting and stopping the vncserver as root.

# service vncserver start
# service vncserver stop

Login to each user and edit the xstartup script. To use Larry as an example, first login as larry.

[~]$ cd .vnc
[.vnc] ls
mymachine.localnet:1.log passwd xstartup

Edit xstartup. The original should look like:

#!/bin/sh

# Uncomment the following two lines for normal desktop:
# unset SESSION_MANAGER
# exec /etc/X11/xinit/xinitrc

[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
twm &

Add the line indicated below to assure that an xterm is always present, and uncomment the two lines as directed if you wish to run the user's normal desktop window manager in the VNC. Note that in the likely reduced resolution and color depth of a VNC window the full desktop will be rather cramped and a look bit odd. If you do not uncomment the two lines you will get a gray speckled background to the VNC window.

#!/bin/sh (-)
# Add the following line to ensure you always have an xterm available.
( while true ; do xterm ; done ) &
# Uncomment the following two lines for normal desktop:
unset SESSION_MANAGER
exec /etc/X11/xinit/xinitrc
[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
twm &

2.5. Start the VNC server

Start the vncserver as root.

# service vncserver start

2.6. Test each VNC user

2.6.1. Testing with a java enabled browser

Let us assume that mymachine has an IP address of 192.168.0.10. The URL to connect to each of the users will be:

Larry is http://192.168.0.10:5801
Moe is http://192.168.0.10:5802
Curly is http://192.168.0.10:5803

Connect to http://192.168.0.10:5801. A java applet window will pop-up showing a conection to your machine at port 1. Click the [ok] button. Enter larry's VNC password, and a 640x480 window should open using larry's default window manager. The above ports must be open in the firewall for the IP addresses or subnets of the client.

2.6.2. Testing with a vnc client

For Larry: vncviewer 192.168.0.10:1
For Moe: vncviewer 192.168.0.10:2
For Curly: vncviewer 192.168.0.10:3

To test larry using vncviewer, vncviewer 192.168.0.10:1. Enter Larry's VNC password, and a 640x480 window sholud open using Larry's default window manager. The vncviewer client will connect to port 590X where X=1,2,3 for Larry, Moe, and Curly respectively, so these ports must be open in the firewall for the IP addresses or subnets of the clients.



:-)

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/10 20:03:38
by gerald_clark
You must open the indicated ports on both the Linux and Windows firewalls.
'Cannot access it' is a bit too vague to provoke a response.
What "exactly" is the problem?

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/10 20:45:27
by aceofblackstar
I receive the following message:

"Firefox can't establish a connection to the server at x.x.x.x:5001."


Since I am testing this from inside the company firewall..... I take it I have to open this port on CentOS server.
Any guidance on how to do this would be appreciated.
I am able to access the nagios service fine.

Thank You

:-)

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/10 20:54:28
by gerald_clark
5801, not 5001.

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/11 12:08:16
by pschaff
Please don't paste in large portions of the Wiki text. We can all read the original page. A reference to the section[s] is sufficient, with perhaps a small quote if there is confusion about a particular piece.

Any feedback that might help improve the Wiki page would be welcome. Hope Gerald's good advice has you on the right track.

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/11 13:53:21
by aceofblackstar
I receive the following message:

"Firefox can't establish a connection to the server at x.x.x.x:5801."


Since I am testing this from inside the company firewall..... I take it I have to open this port on CentOS server.
Any guidance on how to do this would be appreciated.
I am able to access the nagios service fine.

Thank You

Re: CentOS 5.3 How to Remote Destop to server

Posted: 2009/06/11 14:06:04
by gerald_clark
On the Centos machine, run setup and chose 'Firewall configuration'.
On the Windows machine, do what Windows users do to open ports on the Windows firewall.