guestfs-release-notes-1.28(1) Virtualization Support guestfs-release-notes-1.28(1)

guestfs-release-notes - libguestfs Release Notes

These release notes only cover the differences from the previous stable/dev branch split (1.26.0). For detailed changelogs, please see the git repository, or the ChangeLog file distributed in the tarball.


virt-v2v(1) and virt-p2v(1) are tools for converting from foreign hypervisors (such as VMware or Xen) or physical machines, to KVM. These tools were previously a separate project. The code for both tools has been integrated into the libguestfs tree. As part of the refactoring, virt-p2v has been rewritten (from Ruby, now C), and virt-v2v now uses several modern features of qemu which make it run many times faster than before. virt-v2v(1) can import from: VMware vCenter, VMware OVA files, local disk files, libvirt, RHEL 5 Xen. It can output to: oVirt or Red Hat Enterprise Virtualization (RHEV-M), OpenStack Glance, libvirt, qemu, local disk files.

virt-log(1) is a new tool for listing log files from guests. It supports a variety of guests including Linux traditional, Linux using journal, and Windows event log.

virt-builder(1) has a new "--machine-readable" option to make it simpler to consume virt-builder from other programs.

New virt-builder(1) and virt-customize(1) --chmod option.

virt-sysprep(1) will now remove: systemd journals, anaconda logs, lightdm logs, debian-installer files, apt logs, exim logs, ConsoleKit logs, firewalld logs, grubby logs, proftpd logs, libvirt/libxml logs, and several other log files. The virt-sysprep "user-account" operation is now able to remove or keep particular user accounts. (Pino Toscano).

New guestmount(1) --fd option, allowing you to run guestmount captive under another process.

virt-sparsify(1) has a new --tmp option allowing you to precisely control where temporary files are stored.

virt-sparsify(1) can now write to a block device.

virt-customize(1) and virt-sysprep(1) now support adding firstboot scripts to Windows guests.

virt-cat(1), virt-edit(1), virt-ls(1) now support the -m option, allowing you to override automatic inspection of guests and instead specify where to mount partitions (Pino Toscano).

The virt tools now have coloured output: green for OK, red for errors, blue for warnings.

Language bindings

You can build a Python distribution using "make -C python sdist"

Ruby bindings have switched from "Test::Unit" to "MiniTest".

The Java bindings are now compatible with OpenJDK 8 (Pino Toscano).


Oracle Linux is returned as "oraclelinux" (Nikos Skalkotos).

Linux guests which do not have /etc/fstab can now be handled (Pino Toscano).

Minix is returned as "minix" (Pino Toscano).


Aarch64 (64 bit ARM) support has been added.

Inspection and the "guestfs_file_architecture" call can now recognize arm (32 bit) and aarch64 guests.

Libguestfs previously used unsafe libxml2 APIs for parsing libvirt XML. These APIs defaulted to allowing network connections to be made when certain XML documents were presented. Using a malformed XML document it was also possible to exhaust all CPU, memory or file descriptors on the machine.

Since the libvirt XML comes from a trusted source (the libvirt daemon) it is not thought that this could have been exploitable.

This was fixed in libguestfs ≥ 1.27.9 and the fix was backported to stable versions ≥ 1.26.2, ≥ 1.24.9, ≥ 1.22.10 and ≥ 1.20.13. (Thanks: Dan Berrange, Pino Toscano).

This bash bug indirectly affects libguestfs. For more information see:

New APIs

Use these APIs to set individual backend settings.
Convert a directory within the disk image to cpio format.
Fetch precise journal times, see sd_journal_get_realtime_usec(3).
Enhanced versions of "guestfs_lstat", "guestfs_lstatlist", "guestfs_stat" which return nanosecond timestamps.

Libguestfs can now be built with qemu 2.x.

Add support for packaging the appliance on Mageia (Joseph Wang, Thierry Vignaud).

Augeas is now a required dependency.

Flex and bison are now required dependencies.

User-Mode Linux (UML) is no longer a supported backend (although still available). It will be supported again once someone steps in and fixes various regressions and brokenness in the UML (Linux) kernel.

You can now connect gdb to qemu by specifying "LIBGUESTFS_BACKEND_SETTINGS=gdb"

Serial BIOS (sgabios) is now used by the libvirt backend (on x86 only) so that we see early BIOS messages.

For the OCaml virt tools, exceptions are now handled and printed by a common function.

A GCC warning about large stack frames is now enabled by default. Several places that used large arrays and structures on the stack have been fixed.

There is now a test for booting the appliance repeatedly. Useful for finding kernel leaks. See: tests/qemu/qemu-boot.c

There is a test for testing the speed of various qemu features such as virtio-serial uploads and block device writes. See: tests/qemu/qemu-speed-test.c

GCC warnings are now enabled for OCaml-C bindings in the OCaml virt tools.

The code for editing files used by virt-edit(1), guestfish(1) "edit" command, virt-customize(1) --edit option and more is now shared between all these utilities (thanks Pino Toscano).

The FUSE tests were rewritten in C to ensure finer control over how system calls are tested.

The script has been fixed so it should no longer create an empty "BUGS" file if the Bugzilla server is unavailable.

The virt-resize(1) tests now use a stochastic method to ensure much deeper and broader testing.

When the network is enabled, the appliance now uses DHCP to acquire an IP address.

If libvirt is being used then the appliance will connect to "virbr0" (can be overridden by setting "LIBGUESTFS_BACKEND_SETTINGS=network_bridge=<some_bridge>"). This enables full-featured network connections, with working ICMP, ping and so on.

empty (but set) LIBGUESTFS_BACKEND prints libguestfs: error: invalid backend:
libguestfs-bash-completion package contains file /usr/share/bash-completion/completions/virt-log, but no _virt_log() function in that file
typo error in man page of virt-edit
virt-v2v conversions from VMware vCenter server run slowly
virt-v2v: warning: display <graphics type='sdl'> was ignored when converting rhel5 guest with sdl graphics
'copy-file-to-file /src /dest' create file /dest even if command 'copy-file-to-file /src /dest' failed
Can not find "RECURSIVE LONG LISTING" in 'man virt-diff'
virt-v2v does not fstrim data disks and non-mounted filesystems
Exporting 2+ disk guest to RHEV, only one disk shows after import
virt-filesystems: incorrect LVM vg name when listing Fedora 21 Alpha Atomic image filesystems
Option missing --no-selinux-relabel
RFE: Allow qemu-bridge-helper to be used to implement guestfs_set_network
virt-v2v prints warning: /files/etc/fstab/8/spec references unknown device "cdrom"
regression setting root password with virt-builder/virt-customize
virt-v2v -v -x during windows guest conversion will hang at hivex: hivex_open: used block id ……
Improve the error info when converting windows guest with unclean file system
virt-v2v fails to convert win7 guest
RFE: stat calls do not return nanosecond timestamps
futimens() is a no-op via guestmount
guestfish can not restore terminal's output colour when exit guestfish, if the terminal's background colour is black then it will make a inconvenient
virt-customize option '--password-crypto' do not work
Warning shows when converting guests to rhev:chown: changing ownership of ‘/tmp/v2v.u48xag/*.ovf’: Invalid argument
warning shows when converting rhel7 guest:virt-v2v:could not update grub2 console: aug_get: no matching node (ignored)
virt-v2v fails with error: cannot open Packages index using db5
part-get-name give 'libguestfs: error: part_get_name: parted does not support the machine output (-m)' error message when run 'part-get-name /dev/sda 1'
virt-sysprep option '--mount-options' don't work well
Illegal command 'part-get-name /dev/sda1 1' cause libguestfs appliance crashed
virt-v2v prints warning:WARNING:/files/boot/grub/ references unknown device "xvda"
virt-v2v: error: disk sda has no defined format shows when converting xen hvm guest
[RFE] virt-v2 should support convert a domain with using domain's UUID instead of domain name
[RFE] virt-v2 should support convert a guest to a dir-pool with using pool's uuid
virt-sysprep option '--user-accounts' don't work well
virt-v2v fails to convert xen pv guests.
virt-v2v fails to convert esx guests
qemu-img shows error message for backing file twice
No error messages output if append '--format qcow2' after '-a guest.img', guest.img is a raw format image file
virt-builder option '--format' don't work well
RFE: Export to RHEV data domain
No error shows when multiple conflicting options used with virt-v2v
Improve the error info when converting xen guest with no passwordless SSH access configured
Improve the error info when converting guest with no space left
No error shows when converting running guest with virt-v2v
virt-v2v will fail when converting guests with initramfs-*kdump.img under /boot
xen guest will be kernel panic after converted by virt-v2v
Annoying message about permissions of /dev/kvm
libguestfs 'direct' backend should close file descriptors before exec-ing qemu to avoid leaking !O_CLOEXEC fds
virt-sparsify overwrites block devices if used as output files
Empty fstab breaks libguestfs inspection
Guestfs.Error("vgchange_uuid_all: Volume group has active logical volumes")
virt-win-reg manual page is corrupted
root gets an error accessing to a non-root dir on a snapshot guestmount VMDK img
These APIs also need to add to `guestfish -h` command list
mageia package list is incorrect
libguestfs 1.27.13 does not build due to libxml library order
RFE: non-polling mechanism to detect guestmount --no-fork readiness
scrub-file can't handle link file
typo errors in man pages
RFE: virt-builder aliases
virt-builder "proxy=off" setting doesn't turn off the proxy for downloads
virt-sparsify man failes to mention what happens to snapshots within a qcow2 image (they are discarded)
virt-builder: If several repos contain the same os-version images, then they are duplicated in -l output
tar-in-opts execute failed that cause libguestfs appliance crashed
virt-resize: libguestfs error: part_set_name: parted: /dev/sdb: Error during translation: Invalid or incomplete multibyte or wide character
virt-builder cannot write to a block device
Ruby tests fail with latest Ruby
virt-sparsify --in-place cannot sparsify as much as it should
virt-df cannot report used disk space of windows guest when updated to 6.5
virt-builder error: "syntax error at line 3: syntax error"
virt-sparsify overwrites block devices if used as output files
virt-rescue cannot set ≥<rescue> prompt, on Ubuntu 12.04

guestfs-examples(1), guestfs-faq(1), guestfs-performance(1), guestfs-recipes(1), guestfs-testing(1), guestfs(3), guestfish(1),

Richard W.M. Jones

Copyright (C) 2009-2023 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.
2024-01-05 libguestfs-1.52.0