Libguestfs - Dec 2016 - Re: libguestfs error: bridge 'virbr0' not found

Hey,

I am getting this error after using virt-v2v-copy-to-local and trying to
run:
$ virt-v2v -i libvirtxml rhel7.xml -o local -os /var/tmp -of raw

I try to set:
export LIBGUESTFS_BACKEND_SETTINGS=virbr0=ovirtmgmt

with no success and the file /etc/qemu/bridge.conf contains:
allow virbr0

it only worked after creating the bridge, is there other way to import
without creating the bridge?

Thank you,
 Shahar Havivi

Sorry, I didn't see this email yesterday.

On Sun, Dec 11, 2016 at 11:25:12AM +0200, Shahar Havivi
wrote:
> Hey,
> 
> I am getting this error after using virt-v2v-copy-to-local and trying to
> run:
> $ virt-v2v -i libvirtxml rhel7.xml -o local -os /var/tmp -of raw
> 
> I try to set:
> export LIBGUESTFS_BACKEND_SETTINGS=virbr0=ovirtmgmt
The syntax is wrong, it should be:

export LIBGUESTFS_BACKEND_SETTINGS=network_bridge=ovirtmgmt

or whatever bridge you want to use, and you do have to enable it in
/etc/qemu/bridge.conf so that we can use qemu-bridge-helper.
> with no success and the file /etc/qemu/bridge.conf contains:
> allow virbr0
> 
> it only worked after creating the bridge, is there other way to import
> without creating the bridge?
The larger question is why does virt-v2v need a bridge.  That's
because it calls guestfs_set_network (g, 1):

http://libguestfs.org/guestfs.3.html#guestfs_set_network

and that causes the libvirt driver to add a network interface to the
guest:

https://github.com/libguestfs/libguestfs/blob/master/src/launch-libvirt.c#L1387-L1398

So you can get around this using LIBGUESTFS_BACKEND=direct which uses
an entirely different form of networking (SLIRP / qemu user net).

But why does virt-v2v call set_network?  One reason is that old
virt-v2v called it.  Old virt-v2v tried to download and install
kernels, but new virt-v2v doesn't do that.  Does new virt-v2v really
need to call set_network?  I'm actually not at all sure it does.

Maybe the following patch should be added?

Rich.
>From 0f23f89c3f67af91c9f7c96a0ea4f1539037419e Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Mon, 12 Dec 2016 19:28:35 +0000
Subject: [PATCH] v2v: Don't enable the network.

This was required by old virt-v2v, but probably not by new virt-v2v.

Thanks: Shahar Havivi.
---
 v2v/v2v.ml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/v2v/v2v.ml b/v2v/v2v.ml
index d94a704..55c32ed 100644
--- a/v2v/v2v.ml
+++ b/v2v/v2v.ml
@@ -76,7 +76,6 @@ let rec main ()  
   let g = open_guestfs ~identifier:"v2v" () in
   g#set_memsize (g#get_memsize () * 8 / 5);
-  g#set_network true;
   (match conversion_mode with
    | Copying (overlays, _) -> populate_overlays g overlays
    | In_place -> populate_disks g source.s_disks
-- 
2.10.2



-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v

On Mon, Dec 12, 2016 at 07:31:31PM +0000, Richard W.M. Jones
wrote:
> Maybe the following patch should be added?
It turns out no we shouldn't add this patch.  The unconfigure_vmware
function tries to use the network to replace VMware's packages.

We could add instead a --no-network option, but using it
unconditionally would break certain conversions from VMware.

Looks like you will need to fix the libvirt oVirt network bridge.  Did
you try the fixed environment variable mentioned in the previous
email?

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/