netboot broken ?

netboot broken ?

[Knut Petersen]

Hi everybody!

I spent too many hours trying to boot a machine via ethernet.
The nic includes a pxe boot rom, and without any problems I
manage to boot an old DOS disk image and memtest.

There are also no problems to _load_ the linux kernel.

But when it reaches the point of ip autoconfiguration
(I included ip=dhcp on the kernel command line and, of course,
I enabled dhcp autoconfiguration in the .config), nothing works.
It sends dhcp requests, dhcpd answers, and this repeats forever.
Well ... this is the second time dhcpd is asked ... without a
working and basically correct configured dhcpd the pxe boot
rom and pxelinux would have been unable to  load the kernel ?!

Ok, there is the possibility not to use dhcp autoconf but to
give the necessary information via ip=.... to the kernel. That
works. But after ip config the kernel needs to connect the server to
get the port of rpc 100003/2 and 100005/1. Both fail and timeout,
the kernel tells me to try the defaults, fails and panics.

Please don´t tell me that I forget to start nfsd or mountd, that I
did not export the filesystem the kernel tries to mount etc. I
have no problems to mount that directory from other machines
on the network.

I tried a number of recent kernels, the oldest was 2.6.14.

Any ideas? Can anybody please
 - confirm that network booting does still work
 - confirm that it is broken.

Yes, I read Documentation/nfsroot ... and I am willing to update
it if anybody tells me how to boot that machine.

cu,
 Knut

Re: netboot broken ?

[Magnus Damm]

Hi,

On 1/27/06, Knut Petersen <Knut_Petersen@t-online.de> wrote:
> Hi everybody!
>
> I spent too many hours trying to boot a machine via ethernet.
> The nic includes a pxe boot rom, and without any problems I
> manage to boot an old DOS disk image and memtest.
>
> There are also no problems to _load_ the linux kernel.
>
> But when it reaches the point of ip autoconfiguration
> (I included ip=dhcp on the kernel command line and, of course,
> I enabled dhcp autoconfiguration in the .config), nothing works.
> It sends dhcp requests, dhcpd answers, and this repeats forever.
> Well ... this is the second time dhcpd is asked ... without a
> working and basically correct configured dhcpd the pxe boot
> rom and pxelinux would have been unable to  load the kernel ?!

Maybe the kernel device driver doesn't work as expected compared to
the PXE driver. I've heard that the other way around is more likely
though. =) Or maybe the PXE driver does half duplex communication only
but the Linux driver is more advanced and supports full duplex, which
fails for some reason.

Check the duplex, try using a good old hub to force half duplex communication.

Or maybe it is an issue with your DHCP server?

> I tried a number of recent kernels, the oldest was 2.6.14.
>
> Any ideas? Can anybody please
>  - confirm that network booting does still work
>  - confirm that it is broken.

I'm netbooting 2.6.15 (ip=on kernel command line) and it works fine for me.

/ magnus

Re: netboot broken ?

[Bryan O'Sullivan]

On Fri, 2006-01-27 at 08:16 +0100, Knut Petersen wrote:

> Any ideas? Can anybody please
>  - confirm that network booting does still work
>  - confirm that it is broken.

Network booting has been in limbo for years, and hasn't had a lick of
maintenance in approximately forever.  The way forward is supposed to be
via initramfs, but nobody is testing the nfsroot code in there, so it
has a fair probability of not working.

	<b

Re: netboot broken ?

[H. Peter Anvin]

Followup to:  <1138378138.4801.9.camel@obsidian>
By author:    "Bryan O'Sullivan" <bos@serpentine.com>
In newsgroup: linux.dev.kernel
>
> On Fri, 2006-01-27 at 08:16 +0100, Knut Petersen wrote:
> 
> > Any ideas? Can anybody please
> >  - confirm that network booting does still work
> >  - confirm that it is broken.
> 
> Network booting has been in limbo for years, and hasn't had a lick of
> maintenance in approximately forever.  The way forward is supposed to be
> via initramfs, but nobody is testing the nfsroot code in there, so it
> has a fair probability of not working.
> 

Feel free to pull the unified git repository and help test:

git://git.kernel.org/pub/scm/linux/kernel/git/hpa/linux-2.6-klibc.git

I really would appreciate both positive and negative bug reports.

	-hpa