Re: Netboot fails with multiple interfaces, wireless

[Harald Hoyer <harald-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On 05/20/2009 09:11 AM, Seewer Philippe wrote:
>
>
> Warren Togami wrote:
>> Harald,
>>
>> I tried your root=dhcp netboot code.
>>
>> Is it intended that you need both root=dhcp and ip=dhcp? Surely the
>> first implies the second?
>
> I guess a simple patch could set ip=dhcp if root=dhcp is supplied...
>
>>
>> So it does successfully mount and NFS root boot, but as I feared it
>> has trouble due to the presence of a wireless device. One thin client
>> I have is Intel Atom with e1000e NIC and iwlagn wireless. It appears
>> to dhcp once successfully on the eth0 ethernet, but its event-driven
>> nature also tries to launch dhclient again on the wlan0. dhclient
>> complains that dhclient is already running and fails.
>
> That's weird it shouldn't do that, since dhclient is started with an
> interface option.
>
>> dhclient wouldn't have succeeded at all on the iwlagn interface
>> because the firmware is lacking from the initrd, and it isn't
>> associated. Also I don't see when it is ever desired to netboot over a
>> wireless interface.
>>
>> As for excluding wireless interfaces, we should do a few things:
>> - Do not copy wireless drivers into the initrd. You suggested using
>> /etc/modprobe.d/something.conf to blacklist the driver from loading.
>> We would need a way to blacklist the driver during the initrd without
>> blacklisting it on the host system where the initrd is generated. How?
>> - Perhaps we should exclude any interfaces named "wlan*" from ifup and
>> dhclient. This works for most devices, but some wireless drivers call
>> the wireless interfaces "eth*".
>> - I have no idea if it is attempting to ifup and dhclient other
>> devices that appear like wmaster0.
>
> I agree there. Wireless drivers shouldn't be included (yet). As for
> separating ethernet from wireless drivers, why not use 'nm' and
> disregard those drivers that contain 'ieee802011_register_hw'?
>
>>
>> A separate but related matter is what to do if a machine has more than
>> one ethernet interface. It seems the only sane thing you CAN do is
>> ifup and dhclient only on the first interface?
>
> That depends on your definition of sane. See the nfs/networking patches
> I sent in march. They're be able to handle all kinds of weird combinations.
>
> Regards,
> Philippe

Philippe, could you try to rebase your patches on the latest git?
If not, I will do so next week.

Warren, nfs now works for me for:
ip=dhcp
root=dhcp, root=192.168.1.1:/mnt/root, root=nfs://192.168.1.1/mnt/root


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