User manual

Etherboot User Manual
5.2. Other filesystem setups
This tutorial does not cover all possible ways of setting up a diskless client’s initial filesystem. You could
even mount a conventional hard disk. Why would you want to boot "diskless" if you have a hard disk?
Reasons might be: you do not wish to administer the local disk; you want the assurance that a system is
running a kernel from a central server; or you like the speed of network booting. Network booting is one
technique in a toolbox. Techniques can be combined to do what you want. If you are interested in
running the diskless client as an X-terminal, a very common use, you may wish to investigate the Linux
Terminal Server Project (http://www.ltsp.org/).
5.3. Swap over NFS
Swap over NFS can be arranged but you have to patch the kernel source. See here
(http://nfs-swap.dot-heine.de).
Be aware that opinions are divided on NFS swap. Some people think it’s a bad thing because it just kills
the network if you have lots of diskless computers and that you shouldn’t be running into a swap regime
on a diskless computer anyway. Some other people like having a bit of insurance.
Also have a look at the NBD (http://atrey.karlin.mff.cuni.cz/~pavel/nbd/nbd.html) Network Block
Device for swapping over that.
There is also the follow-on project ENBD (http://www.it.uc3m.es/~ptb/nbd/), the Enhanced Network
Block Driver. I have no experience with this for swapping. Comments welcome.
6. Booting DOS
What about DOS? The deal with DOS is that one is loading a virtual floppy called A: into extended
memory and then booting from this floppy. So you have to capture an image of a bootable DOS floppy
first. Some more details can be found in the mknbi-dos (../mknbi.html) utility.
I have booted DOS (both M$ versions up to 5.0 and DR versions up to 7.03) diskless this way. A
mknbi-fdos (../mknbi.html) is available for building boot images for booting FreeDOS, the procedure
differs slightly from booting M$ or DR DOS.
If you were thinking of booting a Windows machine via the network, it seems (I’m not masochistic
enough to do this) the problem is not the network booting but the mounting of a file system over
NetBIOS (Windows does not do remote mounts of root filesystems over NetBIOS on TCP). So that rules
out a Samba server. It appears to be possible over a Netware server, for which Linux or FreeBSD has
workalikes. Also it is said that only certain versions of Windows will allow diskless booting. You will
also have problems with pathnames and the usual Windows hassles. Do you really want to do this? You
do know that you can run lots of desktop applications like Netscape, StarOffice, etc. on Linux, FreeBSD,
etc. now? Why pay good money when you can use equally good free replacements? Anyway if you are
still determined, in the Etherboot home page (http://www.etherboot.org/), there are links to external Web
pages, one explaining how this was done with a commercial TCP/IP boot ROM, another explaining how
to do it using Etherboot and Netbios over IPX. A recent user experience is here
(http://www.geocrawler.com/lists/3/SourceForge/5299/0/8052616/). Good luck and send us your
experiences or better still a URL to a page explaining how you did it.
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