Proxmox Virtual Environment (PVE) 8.4 is the latest release of the open-source virtualization management platform, bringing a host of enhancements and new capabilities. Announced on April 9th of 2025, PVE 8.4 is based on Debian 12.10 “Bookworm” and introduces features that improve VM live migration, storage integration, and guest performance. Bacloud blog post provides a concise overview of all significant new features in Proxmox VE 8.4, compares the changes with the previous version (8.3), and offers clear instructions on downloading and upgrading to this latest release.
Live Migration with Mediated Devices (vGPU support) – Proxmox VE 8.4 enables live migration of running virtual machines that use mediated devices (e.g., NVIDIA virtual GPU). In earlier versions, migrating a VM with an attached vGPU required shutting it down, but now an active VM can be moved to another node if the target has the same hardware and driver support. This update is handy for those using NVIDIA vGPU in clusters – a new helper tool (pve-nvidia-vgpu-helper) is included to simplify configuring the NVIDIA vGPU drivers.
API for Third-Party Backup Solutions – A new backup plugin API allows external backup providers to integrate directly with Proxmox VE’s backup/restore framework. Third-party backup solutions can develop plugins that register in Proxmox, enabling backup and restore operations through the Proxmox UI and API like the native Proxmox Backup Server. This gives administrators more choices for enterprise backups and lets third-party vendors take advantage of Proxmox VE’s built-in backup scheduling, verification, and management features.
Virtiofs Directory Passthrough – Version 8.4 introduces virtiofs support, allowing you to efficiently share host files or directories with guest VMs. Virtiofs bypasses network file systems by letting a VM directly access a folder on the host with minimal overhead. This means significantly faster and simpler file sharing between the host and VM compared to alternatives like network shares. Modern Linux guests have virtiofs support out-of-the-box, while Windows guests can use this feature with a small guest driver installation.
Updated Core Components – PVE 8.4 updates its core virtualization stack to the latest open-source technologies. It runs on Debian 12.10 and uses Linux kernel 6.8.12 by default, with a newer 6.14 kernel available as an opt-in for cutting-edge hardware support. The QEMU hypervisor is updated to version 9.2.0, LXC to 6.0.0 for Linux containers, and OpenZFS to 2.2.7 (with patches for kernel 6.14). Proxmox VE now includes Ceph 19.2.1 “Squid” as a stable, supported storage backend, allowing users to deploy the latest Ceph release for distributed storage.
Other Enhancements—Besides the headline features above, Proxmox VE 8.4 brings many under-the-hood improvements. Backup operations benefit from a more robust backup file system mechanism (reducing the I/O impact on VMs during live backups). The Software-Defined Networking stack has received stability and integration improvements, and the installer now offers additional options for initial setup. Countless bug fixes and minor UI enhancements are also included, as detailed in the official release notes.
Proxmox VE 8.4 is a refinement of the 8.x series, building on the foundation of version 8.3 and introducing critical new capabilities. Here are the key improvements and changes in 8.4 compared to PVE 8.3:
Live Migration of vGPU-Backed VMs: 8.4 is the first release to allow live migration of VMs with GPU passthrough or mediated devices. In PVE 8.3, if a VM was using an NVIDIA vGPU (mediated device), you had to shut it down to move it; by contrast, 8.4 can live-migrate such VMs between hosts (assuming the destination has equivalent GPU hardware and drivers). This is a significant upgrade for high availability in environments leveraging GPU acceleration.
Third-Party Backup Integration: Proxmox VE 8.3 relied on Proxmox Backup Server or other external scripts for backups, with no built-in way to plug in third-party solutions. Version 8.4 introduces an official plugin API for backup providers, which did not exist in 8.3. This means vendors (or open-source projects) can integrate their backup systems directly into Proxmox’s interface. Administrators on 8.4 gain the flexibility to use non-Proxmox backup services with the same level of integration that 8.3 had only with its native backup tools.
Host-Guest File Sharing (Virtiofs vs. 8.3): PVE 8.3 did not support virtiofs, so sharing files between host and VMs required network-based solutions (NFS/SMB shares or the older VirtIO-9P, which had performance limitations). With 8.4, virtiofs is available out-of-the-box, offering a much faster and more seamless file share mechanism. This is a clear improvement over 8.3 for workloads that need to transfer files between the host and virtual machines frequently.
Ceph “Squid” Now Stable: 8.3 and 8.4 support Ceph for distributed storage, but the included versions differ. Proxmox VE 8.3 added preliminary support for Ceph 19 Squid as a tech-preview alongside Ceph 18 Reef. In 8.4, Ceph Squid 19.2.1 is fully supported and considered the stable default Ceph version. This means users can confidently deploy Ceph Squid clusters on 8.4, whereas on 8.3, the default would be Ceph Reef (with Squid only optional). Environments running Ceph will see better performance and new features by moving to 8.4’s Ceph version, and an upgrade path from Reef to Squid is provided for existing clusters.
Underlying System Updates: The core OS and kernel in Proxmox VE 8.4 have been updated relative to 8.3. PVE 8.4 is based on Debian 12.10 and offers a 6.14 kernel option, whereas PVE 8.3 was on Debian 12.8 with an optional 6.11 kernel. The QEMU virtualization engine jumped from version 9.0.2 in PVE 8.3 to 9.2.0 in PVE 8.4, bringing various performance and security improvements. These updates improve hardware compatibility and virtualization performance in 8.4 compared to 8.3.
Backup and Networking Enhancements: Proxmox VE 8.3 introduced several quality-of-life improvements, such as faster container backups to Proxmox Backup Server by skipping unchanged files and a new integration of the SDN (Software-Defined Networking) feature with the firewall (allowing automatic IP sets for virtual networks). Version 8.4 continues this trajectory: backups are made even more reliable thanks to strengthened backup fleecing (reducing the chance of I/O stalls during VM backup), and the SDN stack is further refined for stability and performance. Additionally, the 8.4 installer includes new options that streamline initial network configuration, building on the import/migration tools enhanced in 8.3. In short, many of the improvements first seen in 8.3 have been polished and extended in 8.4, resulting in an even more robust platform overall.
Getting started with Proxmox VE 8.4 is straightforward. Follow these steps to perform a fresh installation of PVE 8.4 on a server or PC:
Download the ISO: Obtain the Proxmox VE 8.4 installation ISO image from the official Proxmox download page. (The ISO contains the complete software bundle, based on Debian 12, for installation on bare metal.)
Prepare Boot Media: Create a bootable USB drive using the downloaded ISO. Tools like Rufus or Balena Etcher can help you make a bootable USB. Alternatively, you can mount the ISO virtually if your server has a remote management interface (IPMI/iDRAC/iLO).
Boot and Install: Boot the target machine from the Proxmox VE 8.4 media. The Proxmox installer will start and guide you through the setup. Select the target hard disk for installation, configure the country/keyboard, set a secure root password and email, and configure the management network interface (IP address) during the wizard.
Complete Installation: After confirming the settings, the installer will partition the disk and install Proxmox VE 8.4. Once it's finished, could you reboot the system? Remove the boot media so the system boots from the hard disk.
Access the Web Interface: After reboot, you can manage Proxmox VE via its web-based GUI. Open a browser on a PC connected to the same network and navigate to https://<proxmox-ip>:8006 (using the IP and port 8006). You should see the Proxmox web interface – log in with the root user and the password you set during installation. You can create VMs and containers from here, define storage, etc.
Note: Proxmox VE is open-source and free to use. Upon installation, you may see a subscription notice (since Proxmox offers paid support subscriptions), but this does not affect functionality. You can use the No-Subscription repository for updates if you do not have an enterprise subscription. The system will be fully functional after installation, and you can later decide to add a license for enterprise repository access if needed.
If you are already running an earlier version of Proxmox VE, you have a clear upgrade path to 8.4. Below are instructions for upgrading from the 8.x series or from the previous major version (7.x):
Upgrading from Proxmox VE 8.0, 8.1, 8.2, or 8.3: Minor version upgrades within the 8.x family are done in-place via APT (the package manager) or through the web GUI. Please ensure you have a recent backup of your VMs/CTs (as a precaution) and then update your system packages. You can upgrade by running the following commands on the Proxmox shell:
This will download and install all updates, bringing your system to 8.4. (If you prefer, you can perform the upgrade through the Proxmox web interface by going to Node > Updates > Refresh > Upgrade.) Once the upgrade finishes, reboot the node to load the new kernel and complete the process. The Proxmox team confirms that upgrading from 8.x to 8.4 via apt is supported and can be done through the GUI. After reboot, you can verify the version in the web interface (look under Node > Summary or via the command pveversion -v).
Upgrading from Proxmox VE 7.x: Moving from the 7.x series (based on Debian 11 “Bullseye”) to 8.4 (Debian 12 “Bookworm”) is a significant upgrade and requires careful planning. Important: Before upgrading, read the official upgrade guide and release notes, and always have verified backups of all VMs and containers. The high-level steps to upgrade from 7.4 to 8.4 are:
Update PVE 7 to Latest—Make sure your existing Proxmox VE 7 installation is fully updated (preferably Proxmox VE 7.4 with all updates applied). This ensures the smoothest transition. You can run apt update and apt full-upgrade on the 7.x system and reboot into the latest 7.x kernel.
Run the Pre-Upgrade Checker: Proxmox provides a script pve7to8 that checks for potential issues (such as deprecated configurations or unsupported sources). Run this script on your 7.x system and review its output. It will flag any problems you think you should address before you try the distribution upgrade.
Adjust Repository URLs: Update your APT repository configuration to point to Debian 12 (Bookworm) sources and the Proxmox VE 8 repositories (enterprise or non-subscription, depending on your setup). In other words, replace any references to bullseye/PVE 7 with bookworm/PVE 8 in files under /etc/apt/sources.list and /etc/apt/sources.list.d/. The official upgrade wiki provides the exact repository entries you need.
Perform the Distribution Upgrade: Now upgrade the OS and Proxmox VE in one go. Run: apt update && apt dist-upgrade (or apt full-upgrade). Accept prompts to proceed, and be prepared to answer questions if asked (for example, about keeping or replacing configuration files – typically, you can keep your existing configs). This step will install Debian 12 and Proxmox VE 8 packages on your system. It may take some time and will download a large number of packages.
Reboot into Proxmox VE 8.4: Once the upgrade command is complete successfully, reboot the server. It should boot into a Proxmox VE 8.4 kernel (Linux 6.2 or 6.8, depending on what is included – note that Proxmox 8 initially uses a 6.2 or 6.1 kernel for Debian 12, and 8.4 updates to 6.8 as default). After reboot, log in and verify the new version by checking pveversion or the web GUI. Ensure that your VMs and containers start correctly. It’s normal to run apt update && apt full-upgrade again after the reboot to catch any remaining updates or finalize package configurations.
Post-Upgrade Checks: Confirm networking, storage, and cluster (if applicable) are all functioning. If you use Ceph, note that Proxmox 8.4 supports Ceph Quincy (17), Reef (18), and Squid (19); you might want to upgrade your Ceph cluster to Squid after upgrading Proxmox VE. The Proxmox documentation guides upgrading Ceph Reef to Squid on Proxmox 8. Also, if you had any third-party repositories or custom configurations, ensure they are compatible with Debian 12 and PVE 8.4.
(If you are running Proxmox VE 6.x or earlier, you must first upgrade to PVE 7 before moving to 8, as direct upgrades skipping a major version are not supported. Follow the upgrade path sequentially — e.g., 6 → 7 → 8.)
Bacloud provides a wide selection of dedicated servers suitable for Proxmox virtualization and offers free Proxmox installation on purchased Bare Metal and dedicated servers, making deployment quick and hassle-free. Additionally, Bacloud offers backup servers with Proxmox Backup Server operating system in different server rooms, ensuring your virtual server infrastructure is always protected and securely backed up. These solutions make Bacloud an excellent choice for users looking for servers to run Proxmox virtualization.
Proxmox VE 8.4 is a major update that increases the platform’s functionality and usability. With features like live migration for vGPU-backed VMs, seamless host-to-guest file sharing, and official support for third-party backup plugins, Proxmox continues to close the gap between open-source virtualization and more costly proprietary solutions. The upgrade brings the underlying system up to date with Debian 12.10 and modern kernels, ensuring better performance and support for new hardware.
This release builds on the advances of Proxmox VE 8.3 – such as SDN improvements and easier VM imports – and takes them further, offering a more robust and flexible virtualization environment. Whether you plan to set up a fresh Proxmox VE 8.4 host or upgrade an existing cluster, the process is straightforward using the official ISO and package management tools. Be sure to leverage the official documentation for a trouble-free upgrade, and enjoy the new features and improvements that Proxmox VE 8.4 offers for your virtualized infrastructure.
Sources: The information above is based on the official Proxmox VE 8.4 release announcement and documentation, including the Proxmox press release highlights and the upgrade guidelines provided by Proxmox developers. For more details, you can check the official release notes and roadmap and the community forum discussion on the 8.4 release. Happy virtualization with Proxmox VE 8.4!