- How Thin Clients Work
- DHCP
- A Trivial Primer On TFTP
- LTSP 4.0 Installation Procedures
- XDMCP
- Help Me!
- Resources
This chapter is from the book
This chapter is from the book
This chapter is from the book
A Trivial Primer On TFTP
Once connected with a proper IP address in hand, your thin client will download a Linux kernel from the server using a protocol called TFTP (Trivial File Transfer Protocol). The package that contains this server may be called tftp-server, which is the name the Red Hat and Mandrake systems I have used here, or tftp, as on my Debian system.
There's not much to getting TFTP running and no real configuration file to speak of. Just make sure the protocol is active. Look in your /etc/xinetd.d directory, and make sure that disable is set to no in the tftp file.
service tftp
{
disable = no
socket_type = dgram
protocol = udp
wait = yes
user = root
server = /usr/sbin/in.tftpd
server_args = -s /var/lib/tftpboot
per_source = 11
cps = 100 2
flags = IPv4
}
It's all very nice and easy (trivial?), but beware of one possible gotcha with the kernel installation. By default, the LTSP kernel, which I will cover shortly, is placed in /tftpboot/lts, whereas some TFTP installations may use a different directory for the TFTP files. For instance, my Mandrake test machine uses /var/lib/tftpboot as the TFTP transfer directory. This will make it impossible for the workstations booting up to download.
You have two choices. The first is to move the lts directory (installed under /tftpboot into your system's official TFTP download directory. Use the line:
mv /tftpboot/lts /var/lib/tftpboot/
The second way is to modify the /etc/xinetd.d/tftp paragraph to reflect the location of the LTSP kernel files.
The line you need to change is the server_args line, substituting /var/lib/tftpboot with /tftpboot. Once the change has been made, restart the xinetd daemon. Which of these two options you choose depends somewhat on whether TFTP is used for anything else on your system. If you are setting it up for LTSP only, it's just as easy to change the xinetd configuration file. Furthermore, it will make it easier to change things when newer kernels become available. The downside is that you have to move any other TFTP files into the new directory. If, instead, you choose to modify the location of the kernel files, then you have to move new kernel files into place each time you upgrade the packages. My personal choice is usually to change the xinetd configuration file.