« previous 1 2 3 4 5 next »

Modest demands

Finding the right server for an LTSP project depends on a small number of variables. There is no exact formula, but a few rules of thumb should be followed. Basically, the amount of memory available takes top priority. RAM is the major player in an LTSP structure, since all applications run on the server. There should be enough of it to allow all users to run their applications at the same time. If the server has to start swapping, performance can be expected to take a nosedive, and it won't matter then whether it's running on a single or a quad-processor machine. The following formula has proven itself in practice as a rule of thumb: Total main memory = 256 MB + (50 MB x number of clients).

These are only typical figures; if all the thin client users want to use Firefox, OpenOffice and a powerful desktop-environment such as Gnome or KDE, then more memory will be needed. If they are content with only the most essential applications in a RAM-saving alternative, and if a lightweight desktop manager such as xfce or icewm is used, less will do the job.

As for the CPU, a multiprocessor system can be helpful, depending on requirements. Here too, the right mix of demand and performance should be determined in advance. A further item requiring attention is the network. Since it has to carry all of the LTSP communications, there should be enough bandwidth for all thin clients, remembering the size of the network. The hard disks should be able to handle an appropriate data rate. If there are more than ten clients, a large amount of data will be involved, and that rules out recycling IDE disks: SCSI or SATA hard disks are a better choice. If the number of clients increases, penny-pinching will not help cope with the heavier load, and professional solutions should be sought.

The project home page says it is not at all unusual to run 50 workstations with Mozilla and OpenOffice on a dual-Xeon 2.4-GHz server fitted with 4 GB of RAM. All in all, when planning an LTSP environment careful thought should be given to how the system will be used and to what demands will be made on it.

Extremely underpowered machines, which are usually inexpensive, can make suitable LTSP terminals. Even discarded workstations can often be used: the Thin Client Requirements Table gives an overview. Besides that, a client needs either a diskette drive or a network card supported by Etherboot or PXE Boot, as well as a graphics card with 2 MB of RAM for an adequate graphical desktop.

« previous 1 2 3 4 5 next »