[Qemu-devel] VM with two interfaces

[Qemu-devel] VM with two interfaces

[Nirmal Guhan]

Hi,

Am trying to create a VM using qemu-kvm with two interfaces(fedora12
is the host and vm) and running into an issue. Given below is the
command :

qemu-kvm -net nic,macaddr=$macaddress,model=pcnet -net
tap,script=/etc/qemu-ifup -net nic,model=pcnet -net
tap,script=/etc/qemu-ifup -m 1024 -hda ./vdisk.img -kernel
./bzImage-1019 -append "ip=x.y.z.w:a.b.c.d:p.q.r.s:a.b.c.d
ip=x.y.z.u:a.b.c.d:p.q.r.s:a.b.c.d root=/dev/nfs rw
nfsroot=x.y.z.v:/blahblahblah"

On boot, both eth0 and eth1 come up but the vm tries to send dhcp and
rarp requests instead of using the command line IP addresses. DHCP
would fail in my case.

With just one interface, dhcp is not attempted and nfs mount of root works fine.

Any clue on what could be wrong here?

Thanks,
Nirmal

[Qemu-devel] Re: VM with two interfaces

[Nirmal Guhan]

On Thu, Oct 21, 2010 at 9:23 AM, Nirmal Guhan <vavatutu@gmail.com> wrote:
> Hi,
>
> Am trying to create a VM using qemu-kvm with two interfaces(fedora12
> is the host and vm) and running into an issue. Given below is the
> command :
>
> qemu-kvm -net nic,macaddr=$macaddress,model=pcnet -net
> tap,script=/etc/qemu-ifup -net nic,model=pcnet -net
> tap,script=/etc/qemu-ifup -m 1024 -hda ./vdisk.img -kernel
> ./bzImage-1019 -append "ip=x.y.z.w:a.b.c.d:p.q.r.s:a.b.c.d
> ip=x.y.z.u:a.b.c.d:p.q.r.s:a.b.c.d root=/dev/nfs rw
> nfsroot=x.y.z.v:/blahblahblah"
>
> On boot, both eth0 and eth1 come up but the vm tries to send dhcp and
> rarp requests instead of using the command line IP addresses. DHCP
> would fail in my case.
>
> With just one interface, dhcp is not attempted and nfs mount of root works fine.
>
> Any clue on what could be wrong here?
>
> Thanks,
> Nirmal
>
Can someone help please? Hard pressed on time... sorry

-Nirmal

[Qemu-devel] Re: VM with two interfaces

[Stefan Hajnoczi]

On Thu, Oct 21, 2010 at 11:49 PM, Nirmal Guhan <vavatutu@gmail.com> wrote:
> On Thu, Oct 21, 2010 at 9:23 AM, Nirmal Guhan <vavatutu@gmail.com> wrote:
>> Hi,
>>
>> Am trying to create a VM using qemu-kvm with two interfaces(fedora12
>> is the host and vm) and running into an issue. Given below is the
>> command :
>>
>> qemu-kvm -net nic,macaddr=$macaddress,model=pcnet -net
>> tap,script=/etc/qemu-ifup -net nic,model=pcnet -net
>> tap,script=/etc/qemu-ifup -m 1024 -hda ./vdisk.img -kernel
>> ./bzImage-1019 -append "ip=x.y.z.w:a.b.c.d:p.q.r.s:a.b.c.d
>> ip=x.y.z.u:a.b.c.d:p.q.r.s:a.b.c.d root=/dev/nfs rw
>> nfsroot=x.y.z.v:/blahblahblah"
>>
>> On boot, both eth0 and eth1 come up but the vm tries to send dhcp and
>> rarp requests instead of using the command line IP addresses. DHCP
>> would fail in my case.
>>
>> With just one interface, dhcp is not attempted and nfs mount of root works fine.
>>
>> Any clue on what could be wrong here?
>>
>> Thanks,
>> Nirmal
>>
> Can someone help please? Hard pressed on time... sorry

Try the #qemu or #kvm IRC channels on chat.freenode.net.  Often people
will respond and debug interactively with you there.

Your problem does not seem QEMU/KVM related.  You'll need to debug the
guest's boot process and network configuration just like a physical
machine.  In fact, I bet with an identical setup on a physical machine
you'd see the same problem.

Double-check the kernel parameters documentation.
See if you have a network configuration in the initramfs or the root
filesystem that would cause it to DHCP and how to pull the
pre-configured settings from the kernel.

Stefan