X Windows Terminal

Revision as of 18:58, 7 April 2006

X Windows can be used in a Server-Client relationship. By setting up your X Windows Server you allow the use of all the programs on that computer to all the client PC's.

There are many advantages of running client computers in this manner:

• They don't even need a hard drive.
• It's silent as there are no moving parts
• The solution saves power as your computers are very thin.
• Everything can be backed up centrally.
• Boot times for client PC's are the fastest around.
• Clients don't need much CPU speed, memory, etc. Because of this they would be very cheap. You could get away with using a Pentium 100Mhz with 32MB ram, no hard drive, no CD-ROM, no Floppy and a fanless power supply. You just need a ethernet card with a PXEBOOT ROM.

Running a single application

To get started I have my server setup running FreeBSD, with X-Windows and a few applications. Nothing too special. Then I have my client PC, which to start off I used the freesbie 1.1 boot CD to perform these initial tests. You can get this from www.freesbie.org. I entered into fluxbox, but you could equally use xfce4.

client# xhost +

This allows all computers to start applications on your client PC. It's dangerous but good for testing everything is setup correctly.

client# ssh <server user@server ip>
eg: ssh mick@192.168.1.1

ssh$ DISPLAY=<client ip>:<client display>; export DISPLAY
eg: DISPLAY=192.168.1.2:0; export DISPLAY

ssh$ xcalc &

This should display on your client

Running a whole X Windows Session (XDM)

server

edit:

/usr/X11R6/lib/X11/xdm/xdm-config

comment out with a '!' the request line

DisplayManager.requestPort: 0

edit:

/usr/X11R6/lib/X11/xdm/Xaccess

to have a single asterisk any where in the file, so the contents should be one asterisk and the rest commented out.

Make sure your firewall has all traffic for you lan. (Need to know which exact ports to allow).

create ~/.xsession for each user which requires access and enter your start up for x eg:

shell#!/bin/sh

startkde

run xdm on server as root

client

make sure your not in X

type this command:

shell# X -broadcast

This assumes that you are running only one server. Otherwise use:

shell# X -query 192.168.1.2

GRUB Floppy boot

(would like to compile this ourselves later) To get started we downloaded the image from www.hp.uab.edu/~ed/grub-net

shell# dd if=/data/grub-net.img of=/dev/fd0

Then we mounted it as msdos Remove/rename menu.1st from the grub directory as it was doing something funny with it. We think that it was looking for a tftp server through our dhcp and we don't have a the dhcp setup correctly here, so we wanted to do it manually.

Reboot off the floppy now..

grub> ifconfig --address=192.168.1.2 --mask=255.255.255.0 --gateway=192.168.1.1
--server=192.168.1.2

OR you can use dhcp

grub> dhcp
 
grub> tftpserver 192.168.1.2

Setup tftp on your server, we created a directory /tftpboot.

Install and setup dhcp

install /usr/ports/net/isc-dhcp3-server

We do this so we can define the root path for the diskless system.

edit /usr/local/etc/dhcpd.conf

option domain-name "iinet.net.au";
option domain-name-servers 203.0.178.191;

# The shared root file system of diskless workstation
option root-path "192.168.1.2:/diskless_ro";

# The server from which to upload the initial boot-file (loads tftp server)
next-server 192.168.1.2;

default-lease-time 3600;
max-lease-time 86400;
ddns-update-style none;

subnet 192.168.1.0 netmask 255.255.255.0 {
        range 192.168.1.10 192.168.1.30;

        # Set up default gateway
        option routers 192.168.1.1;
}

shell# dhcpd

Setting NFS

# mkdir /diskless_ro
# chmod 444 /diskless_ro

# mkdir /diskless_rw
# chmod 777 diskless_rw

Make directories for each IP for your clients

# cd /diskless_rw
# mkdir 192.168.1.XXX
# cd 192.168.1.XXX
# mkdir etc var

Enable NFS /etc/rc.conf

rpcbind_enable="YES"
nfs_server_enable="YES"
nfs_server_flags="-u -t -n 20 -h 192.168.1.2"

Configure /etc/exports

# file systems accessible only for reading:
/usr -ro -maproot=0 -network 192.168.1.0 -mask 255.255.255.0
/diskless_ro -ro -maproot=0 -network 192.168.1.0
        -mask 255.255.255.0

# file systems accessible for writing. All the resources
# given to every diskless station are specified by one line:
#
# Diskless-20
/diskless_rw/192.168.1.20/etc /diskless_rw/192.168.1.20/var \
        -mapall=root 192.168.1.20

Starting NFS

data# rpcbind
data# nfsd -u -t -n 20 -h 192.168.1.2
data# mountd -r

Testing to see if the exports are correct

data# showmount -e
Exports list on localhost:
/usr                               192.168.1.0
/diskless_rw/192.168.1.20/var      192.168.1.20
/diskless_rw/192.168.1.20/etc      192.168.1.20
/diskless_ro                       192.168.1.0

Starting diskless system through GRUB

These commands are half working...
grub> root (nd)
grub> kernel /kernel root=ad0s1a
grub> pxeboot

Completely Diskless System (PXEBOOT ROM)

Running completely diskless by booting from a Network ROM Chip.

Coming soon...

links

http://www.nber.org/sys-admin/FreeBSD-diskless.html

http://www.onlamp.com/pub/a/bsd/2004/09/09/diskless_server.html

http://www.onlamp.com/pub/a/bsd/2004/09/30/diskless_clients.html