Important note

/!\ /!\ /!\ /!\ /!\ /!\ /!\ /!\ /!\ /!\ /!\ /!\

/!\ This page is obsolete (based on Debian Edu/Etch). The most recent manual for network clients (related to Debian Edu/Lenny) is located at http://wiki.debian.org/DebianEdu/Documentation/Lenny/HowTo/NetworkClients and get rid of this page altogether (cf. [http://wiki.debian.org/DebianEdu/Documentation/Lenny/HowTo/NetworkClients#Howtosetupandconfiguredisklessworkstations Chapter: How to set up and configure diskless workstations])

/!\ The old page for etch can be found at http://wiki.debian.org/DebianEdu/HowTo/LtspDisklessWorkstation-etch

Confirmation

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Name

Date

Remark

Valerio Pachera

19/10/2008

ref. also to his posting to d-e-mailinglist on 12.11.2008 11:46

What

This page is suposed to become the instructions in how you can run Diskless workstations from a skolelinux3.0 installation. Diskless workstations are also marketed using the term "LowFat Clients" or "Halfthin Clients" or "stateless workstations".

A diskless workstation is similar to a thin client in that it boots from the network with pxe. But instead of running applications on the server and displaying them on the thin client screen with X. A diskless workstations mounts it's root file system from its next-server, and runs all applications on the local hardware. You can think about it like a regular workstation with a very long hard drive cable.

Why

why not

How

  1. prerequisites
    • a regular skolelinux setup with tjener and preferably internet access
    • a fresh installed skolelinux terra/etch thin client server, that you want to run diskless workstations from (this server is promoted as "next-server" by tjener's dhcp)
    • combined server work fine (You must not edit pxelinux.cfg/default and in dhcpd.conf you must only enable your workstations).
    • swap on each diskless workstation is recommended. Schools has experienced that clients with 256 MB RAM freezes when swap is not enabled. Swap can be run on the server or on local hard drive
    • /!\ enough space on /opt? It need to be at least 3.5 GiB.

    • /!\ enough space on /var? the apt cache must be able to store all the packages you download.

    • /!\ patience and enough time. The ltsp-make-client script downloads and installs the complete Debian Edu into your chroot

          lvextend --size +1G /dev/vg_system/opt
          resize2fs /dev/vg_system/opt
  2. Edit /opt/ltsp/i386/etc/apt/sources.list.
    • Because the CDs and DVD is not signed, one need to use network APT sources.
    • Add the security repository.

deb http://ftp.skolelinux.org/debian/ etch main
deb http://ftp.skolelinux.org/skolelinux/ etch local
deb http://security.debian.org/ etch/updates main

and comment the first line with a '#' character like below:

# deb file:///cdrom etch main local
  1. [optional] the next point is the breaking point of the operation. if it fails you have a semi broken chroot. so i usualy tar up the /opt/ltsp directories to make it easier to try the script several times.
  2. Then run the command /usr/sbin/ltsp-make-client This will adapt your chroot /opt/ltsp/i386 to diskless workstation, and install the packages needed for a workstation there. If it fails for some reason you can delete the broken chroot and restore the orginal from your tarfile and try again with sh -x /usr/sbin/ltsp-make-client to get a more verbose output. (run outside the chroot).
    /!\ This command downloads and installs a complete debian installation into your chroot, so it can take a very long time.
    /!\ you can only run this script once, if it breaks you must restore your tarfile or recreaet the chroot with ltsp-build-client, or debian-edu-ltsp.

If you choose to recreate the chroot with debian-edu-ltsp, you should run

aptitude install sitesummary-client debian-edu-artwork debian-edu-artwork-usplash
debian-edu-archive-keyring ltspfsd
inside the chroot
before retrying ltsp-make-client.

Or, before you run the debian-edu-ltsp do the following:

make this file
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/032-edu-pkgs
and have following line in it
case "$MODE" in
   configure)
         LATE_PACKAGES="$LATE_PACKAGES \
                        sitesummary-client \
                        debian-edu-artwork \
                        debian-edu-artwork-usplash \
                        debian-edu-archive-keyring \
                        ltspfsd"
         DEBCONF_SEEDS="$DEBCONF_SEEDS /usr/lib/debian-edu-install/defaults.ltsp-chroot"
         ;;
esac
And then run debian-edu-ltsp.

Then you are ready to run ltsp-make-client, and here you have #example of a verbose installation, with log in /var/tmp/ltsp-make-client.log

sh -x /usr/sbin/ltsp-make-client | tee /var/tmp/ltsp-make-client.log

This is setup in the file /opt/ltsp/i386/etc/init.d/ltsp_set_runlevel If you want your diskless workstation on the 192.168.0.0/24 network, you may change this here

  1. boot your client.
    • if all went well you should be looking at the kdm login screen
  2. login and use your system
    • /!\ keep in mind your diskless workstations need to be added to your ldap netgroups, just like any other workstation. Otherways it wont be able to mount your HOME dir, and you won't be able to login. For do it, open LWAT / Add machines; insert the mac address of the client network card and the same host name used in the dhcp.conf file (in the example below is "static04"). The athers fields are completed automaticcally. After that you have to wait few minutes or restart the NSCD daemon (didn't test yet, rebooting it works).

Known Problem

1. When the installations come to a point it's stops, you have to press "ctrl+c" 6 times this must be repeted 4 or 5 time.
05.02.2008: This seems to be fixed.

2. If the thinclient not start up the X after the ltsp-make-client, you just have to add the following in the /opt/ltsp/i386/etc/lts.conf file
            SCREEN_07=ldm

example dhcpd.conf snippet

Search the section that start with the comment

# 50 workstations are defined as static00 to static49 on 10.0.2.50-99
# Provide a static address using dhcp by adding their MAC addresses here

And then edit one of the "host static" code like described here (remember to insert your own MAC address):

host static04 {
   hardware ethernet 00:00:00:00:00:00;
   fixed-address static04;
   filename "/var/lib/tftpboot/ltsp/i386/pxelinux.0";
   option root-path  "/opt/ltsp/i386";
   next-server ltspserver00;
   # next-server tjener; # for a combi server
}

example /var/lib/tftpboot/ltsp/i386/pxelinux.cfg/default

DEFAULT vmlinuz ro initrd=initrd.img quiet splash root=/dev/nfs ip=dhcp  nfsroot=/opt/ltsp/i386

(you can only add a boot option for booting a locally installed operating system)

This configuration has been tested and found to work properly.

Resizeing network Swap

Network swap is turned on as default in Etch. But the size of it is rather small. If needed the size of it can be easely changed.

example /etc/ltsp/nbdswapd.conf

SWAPDIR=/var/opt/ltsp/swapfiles
SIZE=512

Using Local Swap

Sometimes it is preferable to use local swap partitions. This is easily done.

example /opt/ltsp/i386/etc/lts.conf

[Default]
        USE_LOCAL_SWAP=Y
        NBD_SWAP=N

Upgrade Kernel

chroot /opt/ltsp/i386
aptitude update
aptitude install linux-image-2.6.18-4-486
exit

Then you must prepare the system to use the new kernel. Exit from the the chroot and run

/usr/sbin/ltsp-update-kernels

When using ltsp in Lenny you must also recreate the image:

/usr/sbin/ltsp-update-image

remember to append "nfsroot=/opt/ltsp/i386" to the file "/var/lib/tftpboot/ltsp/i386/pxelinux.cfg/default" that got overwritten (see previous example ).

Further Reading

Known Problems

With Skolelinux 3.0r0 auto mounting of CD-ROMs though KDE (via popup window) does not correctly. When selecting "Open in new Window" KDE will complain that the file system did not match. A fix is being worked on, until then use pmount:

pmount /dev/cdrom
pumount /dev/cdrom

05.02.2008: Mount of cdroms is working out of the box with Skolelinux 3.0r1.

Note

If this wiki page is moved, also the pointer in $svn/trunk/src/debian-edu-config/sbin/ltsp-make-client needs to be changed