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What is LTSP?


LTSP (Linux Terminal Server Project) provides a low cost platform for diskless worstations used as GNU/ LINUX terminals - run both in a graphical or character mode.

How does LTSP work?

In a standard network a server with an operating system contains data, which is made available for a local network. A workstation running its own operating system is connected to the server on which it runs certain files.

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Network based on workstations equipped with their own hard disks and operating systems
invoice Network based on a diskless terminal

Using LTSP, a diskless workstation receives from DHCP and TFTP its own IP address and a server kernel, then it runs basic system files from the server through NFS. All operations are done on the server but the final result is displayed on the workstations. For this reason, they don't need a lot of RAM memory, fast processors, or large hard disks.

"Normal" workstations versus LTSP

Visually, there is no difference for the end user whether their workstation is equipped with a hard disk or not. In both cases, when the computer is switched on, an operating system is loaded and a typical desktop is displayed. The speed of loading as well as the speed of program execution are also unchanged. The entire network is built the same way, which means that all its computers are connected with a switch (or switches).

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Workstation with an Windows operating system and a running INVOICER MADAR program
invoice Diskless terminal with a running INVOICER MADAR program

Why LTSP?

Easier handling and management of documents

In a typical office there is a computer on every desk, each containing a powerful hard disk, operating system and programs. All the users collect their data on the local hard disks (or on a server) which are hardly ever subject to backup.

While using LTSP no user will ever save a document in the wrong place because all the information is written only on the server. This is a way to ensure a full control over documents and user access.

System resistant to disk failure

Collecting data on a single server and providing an additional disk connected via RAID 1, the administrator receives a data backup. Of course, it is recommended to make additional copies on CD's or other drives to avoid data loss in case of both disk failure or theft, for example.

Before you decide to use LTSP

Advatages:
+ low equipment failure rate
+ full control over data and user access
+ free software
+ high efficiency
+ low cost workstations
+ one operating system (server)
+ easy administration (all settings on one computer)
+ compatible with MADAR program

Disadvatages:
- run only on LINUX operating system.
- network speed - at least 100mb/s

Lower cost

Computers are less prone to fail because workstations don't carry the processing load and are not equpped with hard disks.
With LTSP one can use some inexpensive PC's (around 600 PLN) - a hard disk, CD-ROM's and other drives are not installed. The system will need a network card (most of the new motherboards have one already built-in), which starts the comp. Most of the software is free (OpenOffice, GIMP, Mozilla Firefox, Mozilla ThunderBird). One needs a single operating system, which is installed on a server. Having 20 workstations can save even up to several thousand PLN.

Additionally, the user can install MADAR program. This is how.

Minimum requirements for the terminals:
- Pentium class processor
- 64MB RAM (for system kernel)
- motherboard (any type)
- graphic card (any type)
- network card (any typewith bootrom 100MBit/s)
No need for:
- hard disk
- CD-ROM's
- 1.44 disk drives
- fast processors
- lot of RAM
- large graphic cards


Cost - examples

Estimated cost of 20 workstations using programs and operating systems by Microsoft and Linux.

Microsoft:

  • server with a 64-bit processor, 1GB RAM,
    2xHDD 80GB SATA without a monitor (price ~2.100 PLN)

  • 20 workstations with a 2GHz processor, 256MB RAM, 1xHDD 80GB + LCD monitor
    (price ~33.000PLN)

  • Microsoft Windows Server 2003 Standard for10 stations (price ~4.490PLN)

  • 2x license for 5 additional stations (price ~993PLN)

  • 20 operating systems Windows XP HOME (price ~5.700PLN)

  • 20x Office 2003 (price ~13.600PLN)

           TOTAL: 59.883PLN NET

Linux:

  • server with two 64-bit rpocessors, 2GB RAM,
    4x 80GB SATA without monitor (price ~4.300PLN)

  • 20 workstations with a 2GHz processor,
    128MB RAM + LCD monitor
    (price ~21.800PLN)

  • Suse Linux 9.2 (price 0PLN)


  • licenses (price 0PLN)

  • 20 operating systems available via LAN
    (price 0PLN)


  • OpenOffice on 20 stations(price 0PLN)

           TOTAL: 26.100PLN NET

To add to it additional cost of 21 licenses for ativirus program for Windows (Linux doesn't generally need an antivirus program) will increase the difference to ~36.000PLN.

How to start it?


The description of Suse 9.1 distribution.

In order to install LTSP on the server, one needs the following:

  1. Download files from LTSP.ORG :
  2. The ltsp-4.1-1.iso (CD image) should be burned ona CD with a standard CD burner.
  3. Install ltsp-utils in the root (su -):
    rpm -i ltsp-0.10-0.noarch.rpm
  4. Run ltspadmin
    • Select Configure the installer options, point to the path where the source fiiles are located, in the example they are on a CD, type in the path of the source:
      file:///media/cdrom/ this is just an example, one should select the CD-ROM drive
    • Path where LTSP is to be installed:
      /opt/ltsp-4
    • If HTTP proxy is used, you should type in the adsress. In this case, you should write:
      none
    • If FTP proxy is used, you should type in the address. In this case, you should write:
      none
    • The program will ask whether the data is correct, OK by pressing y
  5. Select Install/Update LTSP Packages - the program will beinstalled and you can move to settings
  6. Configure LTSP - LTSP wil analyze the server with respect to the running deamons (DHCP, NFS, TFTP, Portmapper, and XDMCP).
    After analysis you should select Configure the services manually
    • Runlevel: 5
    • Interface selection: select the network card which is to make the operating system available to other workstations. If there is one, you should type in eth0
    • DHCP configuration: no selection needed. It will be set manually.
    • TFTP configuration: if there is a massage displayed on the screen, which reads"tftp is already enabled and running!" , you can exit and move on, otherwise you should download and install TFTP daemon.
    • Portmapper configuration: "portmap is already enabled and running!" as above.
    • NFS configuration: "nfsd is already enabled and running!" as above.
    • XDMCP configuration: "The Xdmcp service is already enabled and running!" as above.
    • Create /etc/hosts entries: "Do you want to add entries to /etc/hosts (y/n) ?" press "y"
    • Create /etc/hosts.allow entries: as above.
    • Create /etc/exports entries: as above..
    • Create lts.conf file: as above.
  7. Press S to see all the settings.
    dhcp
    tftp
    portmapper
    nfs
    xdmcp
    YES
    YES
    YES
    YES
    YES
    YES
    YES
    YES
    YES
    no
    YES
    YES
    YES
    YES
    YES
    /etc/hosts
    /etc/hosts.allow
    /etc/exports
    /opt/ltsp-4/i386/etc/lts.conf
    YES
    YES
    YES
    YES
    If you can see "no" (except XDMCP by Enabled), it means that some daemons have been misconfigured.
  8. If all is set properly, you can exit the LTSP settings.
  9. Open dhcpd.conf (/etc/dhcpd.conf) and type in:
    ddns-update-style
    default-lease-time
    max-lease-time
    option subnet-mask
    option broadcast-address
    option routers
    option domain-name-servers
    option domain-name
    option root-path
    option option-128 code 128 = string;
    option option-129 code 129 = text;
    subnet 192.168.0.0 netmask 255.255.255.0 {
    use-host-decl-names
    option log-servers

    host jakas_nazwa { "name of terminal"
    hardware ethernet
    fixed-address
    filename
    }

    none;
    21600;
    21600;
    255.255.255.0;
    192.168.0.255;
    192.168.0.10; "adres IP serwera"
    192.168.0.10; "adres IP serwera"
    "ltsp";
    "192.168.0.10:/opt/ltsp/i386";
    "IP address of the server and the path to LTSP "


    on;
    192.168.0.10;


    00:11:2f:03:2c:9c; "MAC adaddress of the terminal network card
    192.168.0.22; "IP addess of the terminal "
    "/lts/nazwa_kernela/pxelinux.0"; "LTSP kernel path"

  10. TFTP must be set to "/tftpboot/"
  11. Add a user to LINUX, like in dhcpd.conf (e.g. using YAST).
  12. In the terminal BIOS you set "boot from the network card" , save the settings and reset the terminal. If properly set up, you should see an operating system loading with a user log-in window.


For further information, contact piotrek@madar.com.pl
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