nfsroot + DHCP

Hi,

I need to mount my root fs over NFS using kernel command line parameter
"nfsroot" and dynamic IP configuration.
Kernel parameter look like (ala grub):
kernel /boot/bzImage ro root=/dev/nfs nfsroot=/rootfs ip=dhcp

I got the DHCP reply for IP, netmask, route, but not for rootserver and
bootserver.

So my question is, what are the DHCP option in need to set to get that
information set?

Thank you,
JP.

Hi Jean-Philippe,

"Jean-Philippe Blais" <(E-Mail Removed)> wrote:
> I need to mount my root fs over NFS

You want to do a diskless boot via dhcp, tftp and nfs?

> I got the DHCP reply for IP, netmask, route, but not for rootserver and
> bootserver.
What you usually set in /etc/dhcpd.conf is

next-server <TftpServerName>;
filename "pxelinux.0";
allow bootp;
allow booting;

All other options come from the pxelinux environment. I managed to do an
unattendet install this way, but I didn't yet manage to do a diskless boot,
so let me know if you get it working.

Christian

Hi Christian,

yes I'm building a floppy image to get a root FS over NFS. I need to do it
using floppy because it is for old HW (486), the floppy and the network is
my only entry point... I also need the root FS over NFS to get a one
floppy set only and automated IP configuration. Also I can't use static
information because it will be use in many (300+) different networks.

So what is the purpose of the pxelinux.0 file and what is suppose to
contain?

Thanks,
JP.

Christian Barmala wrote:

> Hi Jean-Philippe,
>
> "Jean-Philippe Blais" <(E-Mail Removed)> wrote:
>> I need to mount my root fs over NFS
>
> You want to do a diskless boot via dhcp, tftp and nfs?
>
>> I got the DHCP reply for IP, netmask, route, but not for rootserver and
>> bootserver.
> What you usually set in /etc/dhcpd.conf is
>
> next-server <TftpServerName>;
> filename "pxelinux.0";
> allow bootp;
> allow booting;
>
> All other options come from the pxelinux environment. I managed to do an
> unattendet install this way, but I didn't yet manage to do a diskless
> boot, so let me know if you get it working.
>
> Christian

In comp.os.linux.networking Jean-Philippe Blais <(E-Mail Removed)>:
> Christian Barmala wrote:
>> Hi Jean-Philippe,
>> "Jean-Philippe Blais" <(E-Mail Removed)> wrote:
>>> I need to mount my root fs over NFS
[..]

> So what is the purpose of the pxelinux.0 file and what is suppose to
> contain?

"pxelinux.0" IS the PXE bootloader. Try www.ltsp.org docs/howto
and troubleshooting should be useful to you.

Good luck

--
Michael Heiming (X-PGP-Sig > GPG-Key ID: EDD27B94)
mail: echo (E-Mail Removed) | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 442: Trojan horse ran out of hay

Hi Jean-Philippe,

"Jean-Philippe Blais" <(E-Mail Removed)> wrote:
> the floppy and the network is my only entry point...
> I can't use static information because it will be use in many (300+)
> different networks.

If you want to use the floppy, you don't need the TFTP Server and pxelinux.
However you may have create different floppies to reflect your different
configurations.

If you want to rely only on the network, you need:

- A network card with PXE boot rom. There are other alternatives, some of
which are free, but I recently saw a used Intel 100 MBit card with built in
PXE rom, and new mainboards have this capability on board, so this is
probably the best choice.

- A tftp server. It comes with all usual Linux distributions and there are
even some for Windows.

- The file pxelinux.0 may be part of your distirbution. You will usually put
pxelinux.0 under /tftpboot and some configuration files under
/tftpboot/pxelinux.cfg. This file contains the kernel parameters, e.g.
"APPEND initrd=initrd.img root=/dev/ram0". You can have multiple config
files. The network or host ip address is encoded in the filename, so you can
easily centralize your management. bpbatch is an alternative to pxelinux,
but pxelinux is more common.

- A DHCP server, which points to the PXE server: See previous posting.

Christian