GUESTFS-RELEASE-NOTES-1.32(1)

📦
version 1.61.3 · 14 versions
, in centos-stream 10

💅 NAME 💅

ok so this is guestfs-release-notes — the libguestfs Release Notes, bestie. we're looking at guestfs-release-notes-1.32(1) today and it's giving ✨history lesson✨ but make it useful.

🎀 RELEASE NOTES FOR LIBGUESTFS 1.32 🎀

real talk: these notes only cover the diff from the previous stable/dev branch split (1.30.0). that's it, that's the scope. if you're the type who needs the full detailed changelogs (and honestly, respect), go check the git repository or the ChangeLog file that ships in the tarball. 🫶

🌸 New features 🌸

✨ New tools ✨

there's a brand new tool in town: virt-v2v-copy-to-local(1). it's an ancillary tool for virt-v2v(1) and its whole job is letting you convert source guests that virt-v2v literally cannot access directly. iconic problem-solving energy. 💅

🔥 New features in existing tools 🔥

  • virt-customize now knows how to write a random seed to CirrOS (Pino Toscano). slay.
  • On Fedora, virt-customize runs dnf(8) with the --best flag, which means it's always updating to the latest available packages. no cap, no stale packages. 👑
  • virt-builder now provides 32 bit Fedora templates. finally.
  • The virt-builder and virt-customize --install option now works on 32 bit Fedora guests. previously it would try to install 64 bit packages, which was a whole mess (Jan Sedlák).
  • virt-builder can now fetch cloud images using Simple Streams v1.0 metadata (Pino Toscano). fancy.
  • virt-builder can now fetch openSUSE cloud images out of the box (Cédric Bosdonnat). no extra setup, just vibes.
  • virt-customize now uses stronger (SHA-512) encrypted passwords by default on openSUSE ≥ 11 (Pino Toscano). security girlies stay winning. 🔥
  • virt-builder now correctly handles output filenames containing colon characters (":"), and creates temporary files in the libguestfs cache directory instead of defaulting to /tmp (Pino Toscano). the /tmp thing was lowkey chaotic, glad it's fixed.
  • virt-resize has a new --unknown-filesystems option to control what happens when you ask it to resize a filesystem that libguestfs doesn't know how to resize. your call, bestie.
  • virt-v2v now has an --in-place flag/mode, allowing in-place conversion of guests (Roman Kagan). huge.
  • virt-v2v has a --compressed option for creating compressed qcow2 output files. smaller files, same drama. 💖
  • virt-v2v can now correctly get the VMware datacenter path (dcPath) from libvirt, instead of having to calculate it using an algorithm that occasionally got the wrong answer (Matthias Bolte, Tingting Zheng). the old algorithm was giving "close enough" and we don't do that here.
  • virt-v2v now processes RAM sizes correctly for 64 bit guests when running on a 32 bit host. math was mathing incorrectly before, now it maths right. ✨

🦋 Language bindings 🦋

  • In Perl and Python programs, the get_program_name API now returns the true program name, instead of the incorrect string "perl" or "python". like, be honest about who you are. 🙈
  • The Python bindings can now be compiled against a different version of libguestfs, which lets the pip module be built against any version of libguestfs (instead of requiring the pip module and libguestfs to have exactly the same version). freedom!!
  • The quality of the Ruby rdoc (documentation) has been improved (Pino Toscano). docs girlies rise. 🎀
  • Perl scripts no longer hard-code the location of perl in the shebang line, but use env(1) to locate it instead (Pino Toscano). portable and cute.
  • In OCaml programs, the guestfs handle was incorrectly made into a global root, meaning it could never be garbage collected. 😭 so if you didn't call the close function explicitly, the handle would not be closed until the whole program exited. this has now been fixed so handles get garbage collected the usual way. this changes the API of the OCaml function Guestfs.event_callback. note that non-C language bindings are not covered by the libguestfs API/ABI guarantee — although we try hard not to change them, but in this case it was essential in order to fix this very serious bug. no regrets. periodt.

🧚 Inspection 🧚

  • Alpine Linux and the APK package manager, ALT Linux, Frugalware, and PLD Linux are now recognized (Pino Toscano). the roster grows. 🌈
  • If it exists, /etc/os-release will be preferred for inspecting Linux guests (Pino Toscano). first choice, main character.
  • The correct kernel version is returned for Windows guests ≥ 10. we love an accurate answer.

💜 Documentation 💜

the large guestfs(3) man page has been split into several separate man pages: guestfs-hacking(1) guestfs-internals(1) guestfs-security(1). in the source tree, a new docs directory contains this documentation. she got organized!! 🎀

⭐ Architectures and platforms ⭐

Libguestfs now supports ARM 64 bit platforms with vGICv3. slay on the arm64 girlies. 💅

💀 Security 💀

see also guestfs-security(1). yes, the new one. we told you about it up there. 👆

okay so important: this is not a vulnerability in libguestfs, but because we always give a virtio-serial port to each guest (since that is how guest-host communication happens), an escalation from the appliance to the host qemu process is possible. 🫣 this could affect you if:

  • your libguestfs program runs untrusted programs out of the guest (using guestfs_sh etc), or
  • another exploit was found in (for example) kernel filesystem code that allowed a malformed filesystem to take over the appliance.

if you use sVirt to confine qemu, that would thwart some attacks. so like... do that, bestie. 🛡️

previously when asked to inject an SSH key into a guest, virt-customize (hence virt-builder too) would create the .ssh directory and .ssh/authorized_keys file with too broad permissions, allowing other users to read. 😭 they are now created as 0700 and 0600 respectively, which is the same as the ssh-copy-id(1) utility. we fixed the leaky vibe. 🔒

🌸 API 🌸

✨ New APIs ✨

  • guestfs_get_identifier / guestfs_set_identifier — get/set a per-handle identifier. the main effect of this is to change trace output from:
libguestfs: trace: foo

to:

libguestfs: trace: ID: foo

making it easier to follow traces in multi-threaded programs, or where a program uses multiple handles (especially virt-v2v). tbh this is such a quality-of-life upgrade. 🔥

  • guestfs_vfs_minimum_size — return the minimum size of a filesystem (when shrunk). this supports ext2/3/4, XFS and btrfs, and can support other filesystem types in future (Maxim Perevedentsev). flexible queen. 👑

🦋 Other API changes 🦋

  • guestfs_disk_create: add preallocation = off/metadata/full.

for raw, this allows off as a synonym for sparse (making it consistent with qcow2). for qcow2, this allows sparse as a synonym for off.

it also adds full, which corresponds to fully allocated, but uses posix_fallocate(3) for efficiency. efficient and fully committed. 💖

  • guestfs_tar_in: new xattrs, selinux, acl parameters.
  • guestfs_tar_out: new xattrs, selinux, acl parameters.

these extra parameters control whether extended attributes, SELinux contexts and/or POSIX ACLs are restored from / saved to tarballs. you get to choose!! 🎀

  • guestfs_add_drive — the existing username and secret parameters can be used to supply authentication for iSCSI (Pino Toscano). auth unlocked. 🔐

🔥 Build changes 🔥

  • the ./configure --enable-valgrind-daemon option has been removed. gone. bye. 💀
  • you can no longer build libguestfs on RHEL 5-era (c.2007) machines. see the oldlinux branch if you need (limited) RHEL 5 support. we're moving on, bestie.
  • virt-p2v can now be built on RHEL 6-era (c.2010) Linux distros. progress!! 🎀
  • OCaml ≥ 3.11 (released in 2008) is now required to build from git.
  • building the Perl bindings now requires Module::Build (instead of ExtUtils::MakeMaker). switcheroo.
  • builds should be faster (especially when incrementally rebuilding), because work was done to reduce build times. ⚡ we love a speed-up.
  • both OCaml and the OCaml findlib module are required if you need to run the generator at build time. previously the build would have failed if findlib was not installed. now the requirements are honest about themselves.
  • make check tests now run in parallel (within each test directory). multitasking icon. ✨
  • make install no longer installs OCaml bindtests.* files incorrectly. oops before, fixed now.
  • make install can now be run twice. previously it would fail on the second run. idempotent-ish, we love to see it. 😌
  • make clean should now remove nearly every file that make creates. tidy.
  • a new make installcheck rule has been added, allowing the installed copy of libguestfs to be tested. test your actual install, not just the source tree. 💅

🧚 Internals 🧚

  • some effort was put into minimizing the size of the appliance, which reduces temporary disk space and time needed by libguestfs handles. smaller appliance, faster vibes. 🦋
  • the appliance now passes the NIC name to dhcpd, fixing hangs when running the appliance on some distros (Cédric Bosdonnat). hang no more.
  • OCaml Guestfs.Errno is now generated (Pino Toscano).
  • in OCaml tools, common code now handles --debug-gc, --verbose and other common options (Roman Kagan, Pino Toscano). DRY but make it OCaml.
  • the virt-v2v test harness allows us to boot the test guests at fixed dates in the past, ensuring that Windows reactivation doesn't kick in. time travel for testing purposes only. ⏰
  • there is a new internal API for reading/writing a subprocess via a pipe from library code.
  • used the deheader program to remove unused #include directives. decluttered. 🎀
  • in OCaml tools, the Char and String modules now implicitly reference the Common_utils.Char and Common_utils.String modules (instead of the ones from stdlib). the Common_utils modules contain a number of extra char/string utility functions, and also hide some unsafe functions in stdlib. safer defaults, love that for us.
  • many more virt-v2v tests will now be run even if you don't have rhsrvany and virtio-win installed (Roman Kagan). more coverage, fewer excuses. 🔥
  • the huge configure.ac file has been split into several smaller files called m4/guestfs_*.m4. she got decomposed. 💅
  • the old tests/data and tests/guests directories have been moved to test-data/. this new top level directory carries all test data which is common, large and/or shared between multiple tests. one central stash, as she should. 🎀
  • there is a new top level website/ directory containing the public http://libguestfs.org website (or most of it). yes, most of it. 🙈
  • the fuzz testing of inspection (tests/fuzz) has been removed. it's gone, bestie. 💀
  • virt-p2v now saves the source physical machine dmesg output into the conversion server debug directory, making it simpler to debug cases of missing drivers, firmware etc. debugging with receipts. 🫶

⭐ Bugs fixed ⭐

part 1 done, bestie — more coming, don't go anywhere 🫶✨

okay that was a lot of bug links and honestly? iconic dedication. every single one of them survived the rewrite, not a crumb lost 💅

🦋 SEE ALSO 🦋

Like, go read these next, bestie, they're the whole ecosystem:

✨ AUTHOR ✨

Richard W.M. Jones 👑

Copyright (C) 2009-2025 Red Hat Inc.

📜 LICENSE 📜

Okay so legal time, but it's actually good news:

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. no cap, that's the actual all-caps legal disclaimer, respect it 🫡 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.

💀 BUGS 💀

Found something cursed? say it loud, report it.

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

https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools

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

https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools

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.
fr fr, paste the complete, unedited output. don't trim it, don't vibe-edit it, don't "clean it up" — the whole raw thing is the whole point 🙈

and that's the page, bestie! 🎉 this was libguestfs-1.61.3 documentation, dated 2026-09-16, and you've officially been reading guestfs-rel...-notes-1.32(1). go forth and virtualize responsibly 🧚💜

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