Scroll to navigation

virt-v2v-release-notes-1.42(1) Virtualization Support virt-v2v-release-notes-1.42(1)


virt-v2v-release-notes - virt-v2v release notes for 1.42


These are the release notes for virt-v2v 1.42, released on 16th April 2020.

New features

This is the first release where virt-v2v lives in a separate repository from libguestfs. The two projects are now broadly decoupled from one another.

Add a new -o json output mode. Primarily this is used to do conversions to KubeVirt (Pino Toscano).

Use new libvirt "<firmware>" feature to get the source guest firmware (Pino Toscano).

virt-v2v -o rhv-upload new option -oo rhv-disk-uuid allows disk UUIDs to be specified. Also -oo rhv-cafile is now optional (Pino Toscano).

Conversions over ssh now use nbdkit-ssh-plugin(1) instead of the QEMU ssh driver. Similarly nbdkit-curl-plugin(1) is used instead of the QEMU curl driver. This allowed us to add more flexible features such as password authentication, bandwidth throttling (new --bandwidth option), readahead, and automatic retry on network failures.

For Windows guests, QEMU Guest Agent MSI may now be installed (Tomáš Golembiovský).

Other fixes

In -o libvirt mode, support Windows Server 2019 (Pino Toscano).

Fix Ubuntu Server conversions (Pino Toscano).

Fix installation of qemu-ga by only installing arch-specific files in the guest (Pino Toscano).

Delay installation of qemu-ga until after virtio-win drivers have been installed and rebooted (Tomáš Golembiovský).

Save the log from running RHEV-APT installer to allow debugging (Tomáš Golembiovský).

Check RHV cluster exists before trying to convert when using -o rhv-upload mode. Also allows us to detect and reject various other conditions early. (Pino Toscano).

Label nbdkit sockets correctly for SELinux/sVirt (Martin Kletzander).

You can use a block device as the Windows virtio driver ISO.

Multiple fixes to RHV uploads: Set "DISKTYPE" field correctly when converting to RHV and VDSM. Properly clean up on failure. Display disk ID in error messages, and log script parameters, to help with debugging. Multiple code cleanups. (Nir Soffer).

Support conversions to RHV in qcow2 format (Nir Soffer).

Fix detection of disk status and failures after conversion to RHV (Daniel Erez).

Cancel disk transfer and remove uploaded disks on failure of conversion to RHV (Pino Toscano).

Images containing small holes (sparse regions) should now convert faster (Nir Soffer).

The nbdkit-cacheextents-filter(1) is used to accelerate sources which have slow sparseness detection, primarily this means VMware sources using VDDK (Martin Kletzander).

Require at least 100 free inodes on each guest filesystem before doing conversion, since lack of inodes could cause conversion failures (Pino Toscano).

Fix osinfo output for CentOS 8 conversions (Pino Toscano).

VMware tools are now removed from Windows guests automatically in most cases (Pino Toscano).

-i ova mode no longer reads the whole input OVF into memory, but parses it off disk (Pino Toscano).

When converting to OpenStack, we now wait up to 5 minutes (instead of 60 seconds) for the Cinder volume to get attached to the conversion appliance, since in some cases it was taking a long time.

If using a new enough version of nbdkit, virt-v2v logs should be much less verbose.


There were no security-related bugs found in this release.

Build changes

Libguestfs ≥ 1.40 is required, it is now packaged and distributed separately from virt-v2v. For developers you can use a locally built (and not installed) copy of libguestfs.

Libvirt is now required to build virt-v2v. Additionally you will require the OCaml bindings to libvirt (, although a copy is bundled for now (it will be removed later). (Pino Toscano).

Libosinfo is required to build virt-v2v. It is used to query information about guest drivers. (Pino Toscano).

Fixes for OCaml ≥ 4.10. The minimum version of OCaml required is still 4.01, but may be increased to 4.05 in future.

Test conversions of Debian 9 and Fedora 29 (Pino Toscano).

Various fixes to srcdir != builddir (Pino Toscano).

Remove gnulib modules not used by virt-v2v (Pino Toscano).


When converting SUSE guests, always try to install QXL driver (Mike Latimer).

Two new modules (Nbdkit and Nbdkit_sources) factor out generic nbdkit operations and nbdkit source operations respectively.

Format Python code to comply with PEP 8 / pycodestyle (Pino Toscano).

Tests have been moved to the tests/ subdirectory, and manuals to the docs/ subdirectory.

Bugs fixed
virt-v2v does not install qemu-ga on EL8 guest
update-crypto-policies command example is incorrect in virt-v2v-input-xen
[RFE] Make the rhv-cafile optional
Should remove info about "Remove VMware tools from Windows guests" in virt-v2v-input-vmware man page
Can't import guest from export domain to data domain on rhv4.3 due to error "Invalid parameter: 'DiskType=1'"
virt-v2v: Use scp -T in -i vmx -it ssh mode
Delete info "export PATH=/path/to/nbdkit-1.1.x:$PATH" in virt-v2v-input-vmware manual page
virt-v2v should show a message when qemu-guest-agent is installed in guest successfully during conversion
virt-v2v fails to import a guest while cannot find `file_architecture` for a file
[v2v][RHV][Scale] v2v Migration to RHV failed on timed out waiting for transfer to finalize
Unable to maintain static IP address configuration post VM migration
Guest has no disk after rhv-upload converting if target data domain has similar name with other data domain on rhv4.2
Update nbdkit info for vddk in v2v man page
On W2K12r2 rhev-apt does not run non-interactively, causing race when starting rhev-apt service from the command line
Macvtap network will be lost during v2v conversion



Previous release notes covering virt-v2v can be found in the libguestfs project: guestfs-release-notes-1.40(1).


Daniel Erez

Richard W.M. Jones

Tomáš Golembiovský

Martin Kletzander

Mike Latimer

Nir Soffer

Pino Toscano

Ming Xie


Copyright (C) 2009-2020 Red Hat Inc.


This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.


To get a list of bugs against libguestfs, use this link:

To report a new bug against libguestfs, use this link:

When reporting a bug, please supply:

  • The version of libguestfs.
  • Where you got libguestfs (eg. which Linux distro, compiled from source, etc)
  • Describe the bug accurately and give a way to reproduce it.
  • Run libguestfs-test-tool(1) and paste the complete, unedited output into the bug report.
2024-05-07 virt-v2v-2.4.0