[Libguestfs] virt-p2v migration

Richard W.M. Jones
Wed, 01 Feb 2017 17:13:55 -0000

On Wed, Feb 01, 2017 at 04:57:24PM +0000, cmc wrote:
> Hi,
>
> I've been trying to migrate a physical host with two disks (the first,
> sda, is the OS disk and the second, sdb, is a data disk) into a VM,
> and it always fails on the second disk. The first disk, the OS disk,
> migrates fine, but when it starts on the second it fails almost
> straightaway with the following error:
>
> (0.00/100%)^Mqemu-img: Could not open
'/var/tmp/v2vovl811e67.qcow2':
> Could not open backing file: Failed to connect socket: Connection
> refused
>
> I can't see this backing file, but it may be deleted when the process
> fails, as unfortunately it cleans up and deletes not only the
> successfully migrated sda and associated files, but I suspect the
> second as well. Most of the rest of the log can be seen at:
>
> http://theninthdimension.blogspot.co.uk/2017/02/virt-p2v-error.html

What's actually happening is when the conversion server tries to
connect to the second disk, the ssh connection has been dropped, hence
the "backing file" (in fact an NBD server) cannot be connected to.

Refer to the second diagram here:

  http://libguestfs.org/virt-p2v.1.html#how-virt-p2v-works

I don't know why the second connection has been dropped.  Does the
conversion server have ssh timeouts enabled?  Or bash timeouts?  You
can check ClientAlive* settings in /etc/ssh/sshd_config.  Also look
for TMOUT or TIMEOUT environment variables on the conversion server.
You can also look in the logs on the conversion server to see if the
ssh connection was dropped or forced to close, and why.

Rich.

--
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.