How could we use computers, which are not modern and a lot of people want to throw they away? It is simple for people who know how to connect terminals to graphical and efficient clusters. There exists a lot of software for this purpose, e.g. Open Mosix or Corosync. But today I would like to write about something other.
Linux Terminal Server Project (LTSP) is software which allows launching the network terminal based on several services like DHCP, NFT and TFTP. I will try to bring setup LTSP in this particular case. I will describe some useful information which can facilitate the work of a network of terminals.
The principle of operation of LTSP is that all applications are actually running on the server. The user logs on to the terminal, actually logs via XDMCP protocol on account created on the server. The terminal does not even need to be equipped with a hard disk or any drives. Of course, if you want to make this mechanism work, then the server must be running DHCP – a dynamic allocation of IP addresses. The terminals start up over the network through the bottom facilities located on the adapters or floppy receives from the server IP address and TFTP attracts specially prepared kernel.
Once the kernel is downloaded – it takes control over the whole process, assembles itself from the server directory tree using NFS and runs the X server. The server communicates with the server logging daemon (e.g. KDM) using XDMCP protocol and allows the user to log into his account. So to put it simply looks principle of start-up terminals.
If you have not already installed the DHCP server, nfs or tftp, then you must add the appropriate packages. This standard network services are available in almost every major distribution, so it should not cause anyone a problem. Tftpd must be set in inetd or xinetd, depending on what is used by our variant of Linux. The packages which we install will also include LTSP kernel that will be sent to the workstations. Exactly. Kernel and thus we will LTSP in just a moment. On the part of the project we have to download the following packages:
- lts_core – the main package LTSP
- lts_kernel – dedicated kernel for LTSP
- lts_x_core – XFree86 environment for LTSP
- ltsp-x-fonts-i386 – font package
LTSP is on the repository of the system. For the user visually it makes no difference whether working on a “normal” position or diskless terminal. In both cases, when the computer loads the kernel and operating system. The speed of startup and operation of the programs themselves also remains unchanged (depending on the LTSP server performance). The network is constructed in the same way, i.e. all computers are connected to the switch (or switches).
Advantages of using LTSP
- low failure rate of equipment (X-terminals without drives)
- full control of user data (all data saved on the server)
- high performance in relation to expenditure
- low price workstations (unnecessary high computing power, RAM and hard disks)
- one operating system (server)
- easy administration (all settings on one computer)
Disadvantages of using LTSP
- a network of at least 100 Mbps (at more than 10 stations)
- does not support MS Windows.