guestfs-release-notes - libguestfs Release Notes


These release notes only cover the differences from the previous stable/dev branch split (1.18.0). For detailed changelogs, please see the git repository, or the ChangeLog file distributed in the tarball.

New features

libvirt and sVirt (SELinux confinement)

You can optionally use libvirt to launch and manage the backend appliance by:

SVirt (SELinux confinement) is used to secure the libguestfs appliance, if the libvirt backend is selected.

virtio-scsi, larger number of drives, hotplugging

Virtio-scsi is now used by default, if it is available. This greatly increases the number of drives that can be added to a single libguestfs handle (up to 255).

You can now hotplug drives (add and remove drives after launch).

Libguestfs can now handle > 25 disks, in all APIs, tools and tests.

You can label drives when adding them, then refer to them by label (/dev/disk/guestfs/LABEL) instead of having to use device names (/dev/sda).

new library features

POSIX Access Control Lists (ACLs) and Linux filesystem capabilities can now be read and written through the API.

Windows Dynamic Disks are now supported. The metadata can only be read (volumes cannot be modified or created). However the data/filesystems in the volumes themselves can be mounted, read and written (Matthew Booth).

Hivex (Windows Registry editing) is now directly supported through the API, making reading or editing the Windows Registry much more efficient.

Several libguestfs APIs were reimplemented so they no longer have any limits on output. The reimplemented APIs are: guestfs_cat, guestfs_find, guestfs_read_file, guestfs_read_lines, guestfs_write, guestfs_write_append, guestfs_lstatlist, guestfs_lxattrlist, guestfs_readlinklist, guestfs_ls.

virt tools

guestfish touch 'win:c:\new_file' now works as expected.

guestfish has a new --network option, which enables the user network in libguestfs.

You can set GUESTFISH_PS1 to use fancy prompts in guestfish.

rsync, ssh, less and lrzip commands are now available in virt-rescue. In addition, rsync can be used through the API for doing incremental copies.

virt-sparsify uses qcow2 v3 for increased efficiency.

virt-sysprep enhancements:

virt-make-fs can now create virtual floppy disks (VFDs).

guestmount has a --pid-file option, which can be used to avoid a race condition between unmounting the filesystem and using the underlying disk image.

language bindings

Full-featured Lua bindings have been added in this release (thanks to Jerome Vuarand for many suggestions).

In Ruby, optional arguments hash is optional.

In Python, optional arguments now don't use special "sentinel" values, so any integer can be passed as an optional argument.

Erlang bindings now come with examples and tests.

Erlang bindings now handle 64 bit integer parameters correctly.

The automated 'bindtests' now test for 64 bit cleanliness in parameter passing. Several bugs in the bindings were found and fixed as a result.

Better handling of blocking and non-blocking functions should make libguestfs calls more efficient.


Windows guests with unlimited-sized Registries are now supported. By adding the hivex API to the libguestfs API, it is much more efficient and easier to inspect and modify the Windows Registry in guests.

Better support for SuSE guests (Olaf Hering).

Return the architecture of installed applications (John Eckersberg).

Windows 8 is now supported.

Fedora 18 is now supported.

Inspection of ISOs/CDs/DVDs can now use the libosinfo database.


Libguestfs without the appliance can be compiled on Mac OS X (Masami HIRATA).

RHEL 5 is now explicitly supported through the 'oldlinux' branch in upstream git.

PowerPC 64 bit is now supported. Also libguestfs has been examined for endianness bugs and these have been fixed.


A man page for the daemon (guestfsd(8)) is included.


guestfish history file

The $HOME/.guestfish history file is now created with 0600 permissions (instead of 0644 before) so it is no longer world readable.


Old versions of both virt-edit and the guestfish edit command created a new file containing the changes but did not set the permissions, etc of the new file to match the old one. The result of this was that if you edited a security sensitive file such as /etc/shadow then it would be left world-readable after the edit.

This issue was assigned CVE-2012-2690, and is fixed in libguestfs ≥ 1.16.

For further information, see

New APIs

 inspect-list-applications2 (John Eckersberg)
 mke2fs (Wanlong Gao)
 mkswap [added label and uuid optional arguments]
 mktemp (Wanlong Gao)
 shutdown [backported to 1.16 and 1.18]
 tar-in [added compress flag]
 tar-out [added compress, numericowner, excludes flags]
 umount [added force and lazy optional arguments]
 xfs-admin (Wanlong Gao)
 xfs-growfs (Wanlong Gao)
 xfs-info (Wanlong Gao)
 xfs-repair (Wanlong Gao)

In the C API only:



qemu ≥ 1.1 is required (≥ 1.2 preferred).

febootstrap ≥ 3.20 is required.

libvirt is optional, but if you want to use the new libvirt backend for launching the appliance then libvirt ≥ 0.10.2 would be required.

Coverity has been run over the complete codebase, and many issues fixed (thanks Ondrej Vasik, Kamil Dudka).

Functions which previously had no optargs can now be converted to ones with optargs, making extending the API much more flexible. Source and binary backwards compatibility is preserved for users of the API.

The way that libguestfs APIs and structures are represented in the generator has changed to use an OCaml struct instead of a tuple. This makes generator descriptions more flexible and easier to understand. For details see commits 39d1a7db and eb185eef.

Separation of the library code into more files:

POD (documentation) is now generated using a rewritten Perl program instead of pod2* + shell scripts.

Man pages now contain stable dates (Hilko Bengen).

Skipped tests now exit with code 77, so they appear as SKIP: in make check output.

The parallel mount-local test has been rewritten in C (RHBZ#838081).

Ruby 1.8.5 is now supported (though Ruby ≥ 1.9 is preferred).

Perl bindings can be disabled via ./configure --disable-perl (Wulf C. Krueger). Note that Perl is still required in order to build libguestfs.

Java bindings are now enabled/disabled using ./configure --with-java or ./configure --without-java (Wulf C. Krueger).

New configure options ./configure --enable-code-profiling and ./configure --enable-code-coverage.

Multiple fixes to use of 64 bit integers in language bindings.

The appliance backend now uses sgabios instead of vgabios (Dan Berrange).

The ./run script now sets enough environment variables that you can run OCaml, Python, Ruby, Java, GJS, Erlang, Lua programs.

./run --test flag for running tests with minimal output. It also prints the time taken to run each test.

The ./run script now builds up paths cumulatively, meaning that you can use ./run twice, or use the libguestfs and libvirt ./run scripts together.

You can extract a list of external commands required by the daemon, making building the appliance on certain distros easier (Olaf Hering).

The virt-rescue command is now tested during make check.

The generator now removes unused generated files. This helps when going back and forth with git rebase, git bisect, etc.

Tests now run in a separate toplevel tmp/ directory in the source. This allows the directory to be labelled for SELinux (sVirt), and also makes it easier to clean up.

make syntax-check now works to a greater extent, and many problems in the main code that were found by syntax-check have been fixed (thanks Jim Meyering).

Emacs mode (-*- foo -*-) has been added to generated files.

Progress bar output is now sent to /dev/tty so it doesn't end up in the regular output of the program. virt-resize and virt-sparsify now suppress progress bars if stdout is not a tty.

There is now a ./configure --without-libvirt option. This is useful for testing that the code still compiles without libvirt.

There is now an internal mini-library for running commands. This allows us to redirect errors from external commands into events.

Code for handling temporary directories and the appliance cache was completely overhauled.

Code for temporarily ignoring/disabling errors now looks like this:

 guestfs_push_error_handler (g, NULL, NULL);
 guestfs_mkdir (g, "/foo"); /* We don't care if this fails. */
 guestfs_pop_error_handler (g);

The tests/extra directory has gone. The "extra tests" are now split into separately runnable targets, such as make check-valgrind. Use make help to get a summary of the targets.

The lpj option is passed to the appliance kernel when using TCG. This should improve clock stability (thanks Marcelo Tosatti, Olaf Hering).

Bugs fixed

libguestfs tools fail with odd error messages if TMPDIR is not an absolute path

Windows 8 guest disks can't be mounted: "The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option."

libguestfs: migration to /etc/hostname, /etc/vconsole.conf, /etc/locale.conf

virt-df with two -a options displays incorrect disk image name

libguestfs-test-tool pauses when you use --help option

mke2fs API does not apply block device naming translation to journaldevice optarg

SELinux policy ought to allow qemu to write to unconfined_u:object_r:user_tmp_t:s0

RFE: inspect-list-applications does not return the architecture of RPM packages

inspect-list-applications does not list all installed RPM packages with same name and different versions

guestfish printed paths are not canonicalized

Progress bar output should go to tty(?) stderr(?)

virt-sysprep reports Guestfs.Error("read_lines: fopen: /etc/sysconfig/network: No such file or directory") on some Fedora guests

libguestfs fail to list devices added by add-drive-ro-with-if twice

virt-inspector fail to work with some windows guests

virt-sparsify should use a more robust method to detect the input format

libvirt doesn't label console, serial sockets

virt-rescue in Fedora 18 is completely broken

libguestfs inspection limits registries to 100 MiB

virt-sparsify --compress fails if output is raw format

RFE: allow extra arguments (like --exclude) to tar-out

tar-out should allow (or force) --numeric-owner

guestfish "copy-out / localdir" command fails with "No such file or directory"

Long filenames on NTFS cause tar-out, copy-out etc to fail with error "Cannot open: File name too long"

RFE: Need help designing and implementing selinux policy for libguestfs/sVirt

virt-make-fs / tar-in should support vfat properly

guestfish touch problem - case_sensitive_path API expects the file to exist

Data loss when writing to qcow2-format disk files

lvresize, lvresize-free fail unnecessarily if you don't change the size of the LV: "New size (nn extents) matches existing size (nn extents)"

compress-device-out didn't support bzip2

guestfish unrecognized mount option gives confusing error message

Filenames containing Chinese characters can't be created on vfat filesystems

virt-make-fs cannot create vfat filesystem containing filesystems with Chinese characters

virt-make-fs -t fat fails with an obscure error message

Inspection fails when /etc/HOSTNAME is empty

libguestfs cannot get icon for Windows 8

Ubuntu install CDs from oneiric onwards are not recognized: "multi-boot operating systems are not supported"

libguestfs doesn't recognize Windows Dynamic disks in some configurations, eg. spanned

Not all febootstrap messages are redirected to log callbacks

libguestfs inspector code cannot handle /dev/disk/by-id/* paths

part-get-bootable gives wrong result with an unordered part layout


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.


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