problem using netboot and root nfs

[Martin Dudle <dudle@ifi.unizh.ch>]

hi there

i'm stuck with the following problem:

using netboot 0.6.1 to boot a 2.0.30 kernel via network. root filesystem
gets mounted by nfs. the whole thing actually works to the point
after root filesystem was mounted by the client. i took a look
to the kernel sources. there i saw that (since execute_command is NULL)
it tries to execve() /etc/init, then (if it fails) /bin/init, then
/sbin/init. /sbin/init should be executed since it's on the root fs.
unfortunately it isn't. i don't get any error messages, too.
next in the kernel comes a while(1) loop that tries to execute
/bin/sh (using kernel_thread()). but not shell ever gets started.
kernel_thread() seems to work since it returns pids that increase and
make sense.


a look at the ethernet shows lots of traffic as follows:

client.33f9e941 > server.nfs: 116 lookup [|nfs]
server.nfs > client.33f9e941: reply ok 28 lookup [|nfs]

client.33f9e942 > server.nfs: 96 readlink [|nfs]
server.nfs > client.33f9e942: reply ok 36 readlink [|nfs]

and so on. there's always a lookup and then a readlink.


i setup my /etc/exports on ther server as follows:
/tftpboot/client	<servers ip number>(rw,no_root_squash)


showmount -e on the server shows that the directory is really exported
to the client at present time.


hardware: two pentium running linux kernel 2.0.30. client network card
is an smc with the dec 41140 chip (tulip driver). server network card
is a ne2000 card. client 16mb ram, server 64mb ram. no scsi or ide disk
on client installed.


if i install a local disk on the client an boot linux, i have no
problems accessing the server via net or mounting filesystems by nfs
from the server.


i wasn't able to find kernel_thread() sources to have a closer look
and find out why it fails to execute a program. unfortunately i'm
not a kernel. any hints where i can add debug statments to
kernel_thread()?


i guess something's now working with the nfs. it just doesn't seem to
be able to execute programs.
i created the filesystem to be exported according to the howto.

any help is _highly_ appreciated! if you post, please add a cc to
dudle@ifi.unizh.ch. thanks a lot,

-martin