Rebuilding libvirt on Ubuntu 24.04 with CLVM + sanlock patch

Background
Prerequisites
Fetch the libvirt source (from Launchpad / Ubuntu archive)
- Create a deb-src sources file (example)
Prepare the build environment
Apply your patch
Update debian/changelog
Build the package
Install and test
Notes and troubleshooting
References

This post documents how to fetch, patch and rebuild libvirt (libvirt 10.0.0) on Ubuntu 24.04. The instructions show how to obtain the original source (Launchpad / Ubuntu archives), install build dependencies, apply local patches, and produce installable .deb packages.

The upstream Ubuntu libvirt source and recent packaging patches are available on Launchpad: https://launchpad.net/ubuntu/+source/libvirt

Background

Ubuntu publishes libvirt source packages via Launchpad. Rebuilding the package locally lets you test small runtime fixes, patches for clustered LVM workflows (CLVM + sanlock / lvmlockd), or other custom changes while keeping the Debian/Ubuntu packaging intact.

If you’re coming from other distributions, the high-level flow is similar: get the source, apply patch, build a binary package, then install. Debian/Ubuntu packaging applies patch files listed in debian/patches/series. You don’t need to use quilt — simply place your patch under debian/patches/ and update the series file. Working directly with the debian/ tree keeps your changes reproducible for package rebuilds and uploads.

This post complements a companion guide for Oracle Linux 9 where I rebuilt libvirt-daemon-driver-storage-logical and applied a CLVM + sanlock patch to handle LV lock conflicts during logical pool activation. See Rebuilding libvirt on Oracle Linux 9 with CLVM + sanlock patch for the original patch rationale and an example vgchange failure message.

Prerequisites

On Ubuntu 24.04 install the usual packaging toolchain and build deps:

sudo apt update
sudo apt install -y build-essential devscripts dpkg-dev fakeroot git curl
sudo apt install -y dh-make dh-sequence debhelper pkg-config

You’ll also need the specific build-dependencies for libvirt. The easiest way is to install them from the archive once you have the source directory:

# in the source directory (see next step)
sudo apt-get build-dep -y libvirt

Fetch the libvirt source (from Launchpad / Ubuntu archive)

You can fetch the source package from Launchpad or via apt source (see options below).

Download from Launchpad (recommended):

Using dget (from devscripts) to fetch and unpack the .dsc file:

# install dget if needed
sudo apt install -y devscripts
# fetch and unpack the source package (example .dsc URL from the package page)
dget -xu https://launchpad.net/ubuntu/+archive/primary/+sourcefiles/libvirt/10.0.0-2ubuntu8.12/libvirt_10.0.0-2ubuntu8.12.dsc

Or manually download the .dsc and tarballs and extract with dpkg-source:

Use apt source (alternative — convenient when deb-src entries are enabled):

# enable deb-src in /etc/apt/sources.list (if necessary) and update
sudo sed -n '1,200p' /etc/apt/sources.list
# then
sudo apt update
apt source libvirt
# or request the exact version
# apt source libvirt=10.0.0-2ubuntu8.12

Both approaches produce the same unpacked source directory (e.g. libvirt-10.0.0/) ready for patching.

Create a `deb-src` sources file (example)

If you prefer to add a deb-src sources file instead of editing existing deb822 files, create /etc/apt/sources.list.d/ubuntu-debsources.sources (note the .sources extension) with the following content (example file included in this repo at assets/ubuntu-debsources.sources):

sudo tee /etc/apt/sources.list.d/ubuntu-debsources.sources > /dev/null <<'EOF'
Types: deb-src
URIs: http://nl.archive.ubuntu.com/ubuntu/
Suites: noble noble-updates noble-backports
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg

Types: deb-src
URIs: http://security.ubuntu.com/ubuntu/
Suites: noble-security
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
EOF

sudo apt update
sudo apt-get build-dep -y libvirt

Remove the file once you’re done if you prefer:

sudo rm /etc/apt/sources.list.d/ubuntu-debsources.sources && sudo apt update

Prepare the build environment

Debian/Ubuntu packaging applies patch files listed in debian/patches/series. You don’t need to use quilt — simply place your patch under debian/patches/ and update the series file. Working directly with the debian/ tree keeps your changes reproducible for package rebuilds and uploads.

Apply your patch

To apply a patch to the DEB source tree, add it to debian/patches (preferred for reproducible packaging):

# copy your patch file into the source tree
cp ~/my-patches/clvm-sanlock.patch debian/patches/
# add to series (ensure correct ordering)
echo "clvm-sanlock.patch" >> debian/patches/series

Update debian/changelog

Debian/Ubuntu policy expects the changelog to reflect local changes. Use dch from devscripts to add an entry for your rebuild:

dch -i "Apply CLVM/sanlock LV activation patch: shared VG visibility, exclusive LV activation for VM disks"

This ensures package versioning and changelog information are correct for building and later uploads.

Build the package

Use debuild or dpkg-buildpackage to build the binary packages. A typical local build step:

# from inside libvirt-10.0.0/
debuild -us -uc -b
# or
# dpkg-buildpackage -us -uc -b

-us -uc skip signing for quick local builds. The -b switch builds binary packages only.

When the build completes successfully, resulting .deb files will be in the parent directory (../).

Install and test

Install the rebuilt packages with dpkg -i (you may need to restart services):

cd ..
sudo dpkg -i libvirt-daemon* libvirt0* libvirt-clients* || sudo apt -f install -y
sudo systemctl restart libvirtd

Check the journal and libvirt logs for errors:

journalctl -u libvirtd -b --no-pager
sudo tail -n 200 /var/log/libvirt/libvirtd.log

Validate the specific CLVM or LV activation behavior: try creating/activating logical pools, creating VM LVs while another host holds locks, and observe whether vgchange/lvchange calls are invoked with the intended activation flags.

Notes and troubleshooting

If packaging scripts or tests fail, first try building with DEB_BUILD_OPTIONS=nocheck to skip runtime tests while debugging packaging issues.

DEB_BUILD_OPTIONS=nocheck debuild -us -uc -b

Ubuntu packages sometimes split libvirt into multiple binary packages; ensure you rebuild and install the relevant libvirt-daemon and libvirt-daemon-driver-storage-logical packages.
If you maintain multiple patches, prefer keeping them under debian/patches with a clear series ordering; this makes uploads and reproduction simpler.
For source control, consider importing the upstream source into a git repo and using git-buildpackage or gbp for finer control over patch branches and uploads.

References

Launchpad libvirt source: https://launchpad.net/ubuntu/+source/libvirt
Debian packaging with quilt: https://www.debian.org/doc/manuals/maint-guide/dpatch.html
debuild / dpkg-buildpackage docs: man debuild, man dpkg-buildpackage

Date: March 1, 2026

Tags: Linux Libvirt