PXE boot seems to use incorrect NFS root

Eduardo Viruena Silva mrspock at esfm.ipn.mx
Mon May 26 02:43:37 PDT 2003

On Mon, 26 May 2003, William Rose wrote:

> Hi,
> I'm trying to set up my gateway machine to offer a FreeBSD live boot to
> PXE capable clients, namely my Compaq TabletPC.  The TabletPC has a
> Intel Pro 100/M, which seems to work fine (after I patched the if_fxp.c
> file with the new device id).  I have working TFTP, DHCP and NFS servers
> (as far as I can tell).  I have a generic kernel plus options BOOTP,
> I have created a new diskless root manually -- not by using the
> technique suggested in the article on freebsd.org.  But I've fixed
> /etc/fstab to reflect the NFS mounted root.  I'm not trying to run X
> (yet).  This is more to get a booting FreeBSD on a system that does not
> have a CD-ROM, floppy or normal keyboard (USB keyboard and mouse only).
> So I tend to run into problems as I can't get usbd to run, and this is
> why I have only been able to do very limited debugging.
> What happens is that the PXE code runs, gets an IP address and loads the
> pxeboot program via TFTP.  This is then able to mount the NFS volume I
> specify in the root-path option in /etc/dhcpd.conf.  It loads the kernel
> and modules, boots, detects devices (including my NIC), and runs DHCP to
> get an IP again and the root-path so it can mount the NFS root.
> It fails shortly thereafter:
> [snipped up to DHCP Ack with option root-path]
>   Adjusted interface fxp0
>   Shutdown interface faith0
> * Mounting root from nfs:
>   no such device 'pxeboot'
>   setrootbyname failed
>   Interface fxp0 IP-Address Broadcast
> [blah blah blah]
>   fstab: /etc/fstab:0: No such file or directory
> [blah blah blah]

You did not say which version of FreeBSD you are using.

Diskless boot has two steps implemented by
scripts:  /etc/rc.diskless1 and /rc.etc/diskless2.

If you have /conf/default/etc, this directory is copied in
a memory file system where /etc is mounted.  If you
have /conf/client_IP/etc then you can configure a particular
client in there, depending on its IP.

As you can see, the process above can overwrite your /etc/fstab/
in two different points.

Now, it seems to me you are not setting "/etc/fstab" correctly.
Look at mine:

Isabeau:/usr/diskless/rootfs/etc> cat fstab     /       nfs     rw      0       0                     /usr    nfs     rw      1       1

are you sure your /etc/fstab says:  "nfs" after the mounting points?

> ... and drops to a shell I can't use (keyboard has stopped working now).
> The value on the line marked by (*) seems to be coming from the
> /etc/fstab on the exported /pxeboot root fs I have created (not option
> root-path as I expected).

nop, this is mounted by your kernel.

> Is this all my own silly fault for not using the approved technique?

of course not.

> What have I left out?  I can send snippets of dhcpd or other
> configuration files if helpful.

please post /etc/fstab

> cheers,
> Will

More information about the freebsd-questions mailing list