Many thanks for this!  I was just reading through the pxe booting stuff 
at:

   http://linux.web.psi.ch/livecd/diskless.html

and thought I'd followed the instructions closely enough but kept getting 
the boot failing 'cos I'd used a hostname rather than an IP address in the 
nfsroot definition.  After that it worked like a charm.

I'm a little bit puzzled why a hostname doesn't work, by the time the 
mount is attempted the dhcp client has already obtained a list of 
nameservers and seems to have filled in resolv.conf.  Maybe the initrd 
environment just hasn't got support for DNS lookups.  I'll look more 
closely this afternoon but just thought I'd ask first...

When doing the nfsroot thing is there a good reason to keep everything in 
squashfs?  ie for testing a custom version can I arrange to just have a 
suitable plain sl (installed) tree nfs mountable by clients?  That will 
let me fairly easily tweak the set of packages and config until I'm ready 
to build a set of custom .iso files...

I'm considering making some custom local net-boot images - partly to 
test/diagnose machines (though the standard livecd seems to contains 
pretty much all one would need) and maybe to run some information displays 
(they just need to boot with a slightly weird X config and automatically 
run a web browser pointing at a suitable URL)...

Obviously in such a setup one wouldn't want to nfs mount the nfsroot rw so 
it would still need some kind of unionfs/aufs magic (at least for things 
like /tmp etc).

-- 
Jon Peatfield,  Computer Officer,  DAMTP,  University of Cambridge
Mail:  [log in to unmask]     Web:  http://www.damtp.cam.ac.uk/