Startup of multiple Guests

Startup of multiple Guests

[Dan Johansson]

Hi, It's me again.

After some time with a lot to do outside the computer world, I am now 
continuing my "KVM-Project". I have gotten all my KVM-Guest to run separately, 
but when I try to start more then one at the same time I get the following 
error message and the second Guest does not start:

warning: could not configure /dev/net/tun: no virtual network emulation

The scripts used to start the Guests looks like this:
Guest-A:
kvm \
        -net nic,vlan=1,model=rtl8139,macaddr=DE:ED:BE:EF:01:04 -net 
tap,vlan=1,ifname=qtap1,script=no,downscript=no \
        -net nic,vlan=3,model=rtl8139,macaddr=DE:ED:BE:EF:03:04 -net 
tap,vlan=3,ifname=qtap3,script=no,downscript=no \
        -m 2048 -k de-ch -vnc :4 -daemonize \
        Robbie.qcow2

Guest-B:
kvm \
        -net nic,vlan=1,model=rtl8139,macaddr=DE:ED:BE:EF:01:03 -net 
tap,vlan=1,ifname=qtap1,script=no,downscript=no \
        -net nic,vlan=3,model=rtl8139,macaddr=DE:ED:BE:EF:03:03 -net 
tap,vlan=3,ifname=qtap3,script=no,downscript=no \
        -m 2048 -k de-ch -vnc :3 -daemonize \
        Wilmer.qcow2

I suspect that something is not 100% correct with my network setup.
I want both of the Guest to be able to access the same qtap's (1 and 3).
br1 = qtap1 + eth1
br3 = qtap3 + eth3

Is it not possible to use the same qtap for two different Guests?
Do I need to setup one qtap for each Guste and configure it like this:
br1 = qtap1a + qtap1b + eth1

Just asking for some advice before I start fiddling around with my network-
setup again. (;-)

Regards,
-- 
Dan Johansson, <http://www.dmj.nu>
***************************************************
This message is printed on 100% recycled electrons!
***************************************************

Re: Startup of multiple Guests

[Amos Kong]

On Sun, May 2, 2010 at 9:14 PM, Dan Johansson <kvm@dmj.nu> wrote:
> Hi, It's me again.
>
> After some time with a lot to do outside the computer world, I am now
> continuing my "KVM-Project". I have gotten all my KVM-Guest to run separately,
> but when I try to start more then one at the same time I get the following
> error message and the second Guest does not start:
>
> warning: could not configure /dev/net/tun: no virtual network emulation
>
> The scripts used to start the Guests looks like this:
> Guest-A:
> kvm \
>        -net nic,vlan=1,model=rtl8139,macaddr=DE:ED:BE:EF:01:04 -net
> tap,vlan=1,ifname=qtap1,script=no,downscript=no \
>        -net nic,vlan=3,model=rtl8139,macaddr=DE:ED:BE:EF:03:04 -net
> tap,vlan=3,ifname=qtap3,script=no,downscript=no \
>        -m 2048 -k de-ch -vnc :4 -daemonize \
>        Robbie.qcow2
>
> Guest-B:
> kvm \
>        -net nic,vlan=1,model=rtl8139,macaddr=DE:ED:BE:EF:01:03 -net
> tap,vlan=1,ifname=qtap1,script=no,downscript=no \
>        -net nic,vlan=3,model=rtl8139,macaddr=DE:ED:BE:EF:03:03 -net
> tap,vlan=3,ifname=qtap3,script=no,downscript=no \
>        -m 2048 -k de-ch -vnc :3 -daemonize \
>        Wilmer.qcow2
>
> I suspect that something is not 100% correct with my network setup.
> I want both of the Guest to be able to access the same qtap's (1 and 3).
> br1 = qtap1 + eth1
> br3 = qtap3 + eth3
>
> Is it not possible to use the same qtap for two different Guests?

No, all the 'ifname' should be different.

try this:
--------
Guest-A:
kvm \
       -net nic,vlan=1,model=rtl8139,macaddr=DE:ED:BE:EF:01:04 -net
tap,vlan=1,ifname=qtap1,script=no,downscript=no \
       -net nic,vlan=3,model=rtl8139,macaddr=DE:ED:BE:EF:03:04 -net
tap,vlan=3,ifname=qtap3,script=no,downscript=no \
       -m 2048 -k de-ch -vnc :4 -daemonize \
       Robbie.qcow2

Guest-B:
kvm \
       -net nic,vlan=1,model=rtl8139,macaddr=DE:ED:BE:EF:01:03 -net
tap,vlan=1,ifname=qtap1b,script=no,downscript=no \
       -net nic,vlan=3,model=rtl8139,macaddr=DE:ED:BE:EF:03:03 -net
tap,vlan=3,ifname=qtap3b,script=no,downscript=no \
       -m 2048 -k de-ch -vnc :3 -daemonize \
       Wilmer.qcow2
~