The new version, based on Debian 13 “Trixie,” celebrates Proxmox’s 20th anniversary with a more modern architecture, greater scalability, and automation for enterprise and hybrid cloud environments.
Proxmox Server Solutions GmbH, an Austrian company specializing in open-source data center solutions, has announced the release of Proxmox Backup Server 4.0, a key update marking a new milestone in two decades of innovation. This version introduces native support for S3-compatible object storage, improvements in ZFS management, and new automation features that strengthen its position as a robust and flexible alternative in enterprise backup solutions.
Main Highlights: Faster, Scalable, and More Automated
1. Updated Base: Debian 13 “Trixie” and Linux Kernel 6.14
Version 4.0 is built upon Debian 13 “Trixie”, ensuring increased stability, security, and compatibility with modern hardware. It also includes Linux 6.14 kernel and ZFS 2.3.3 filesystem, enhancing disk performance and storage reliability.
2. Native Support for S3 Storage
One of the most anticipated features is the native support for S3 object storage backends, compatible with public services like Amazon S3 or private clouds. This functionality allows for more efficient and cost-effective backup scaling, leveraging:
- Smart local cache to reduce API calls to the backend.
- Disaster recovery robustness, even if the original server fails.
- Exclusive management of each datastore by a single instance, with reusable data.
3. Dynamic RAIDZ Expansion in ZFS
Thanks to ZFS 2.3.3, it is now possible to perform hot expansion of RAIDZ, adding disks to an existing pool without service interruption. This facilitates gradual storage scalability without initial over-provisioning or long downtimes.
4. Automatic Synchronization for Ejectable DataStores
With the new run-on-mount option, synchronization tasks run automatically when mounting an ejectable datastore, simplifying backup processes on external devices and ensuring data consistency in environments with media rotation.
Integration with Proxmox VE and Availability
Proxmox Backup Server 4.0 is designed for seamless integration with Proxmox Virtual Environment (PVE). Simply add a datastore as a backup target to start protecting VMs and containers with deduplication, compression, and authenticated encryption.
The new version is already available for download as an installation ISO for bare-metal or as an install on existing Debian systems. Upgrades from version 3.x are supported, and Proxmox provides a detailed migration guide.
Free License with Commercial Support
As is customary in the Proxmox ecosystem, Backup Server 4.0 is open-source software released under the GNU AGPLv3 license, allowing free use in both commercial and personal environments. For businesses requiring professional support, Proxmox offers enterprise subscriptions starting at €540 per server, including access to validated repositories, technical support, and regular updates.
Celebrating 20 Years of Technological Independence
Proxmox marks 20 years as a leader in open-source infrastructure solutions. Its focus on technological independence, reducing total cost of ownership (TCO), and eliminating vendor lock-in has established it as a genuine alternative to proprietary solutions such as Veeam, Commvault, or Acronis.
With Proxmox Backup Server 4.0, the company reinforces its commitment to an efficient, sustainable, and user-controlled IT infrastructure, essential for sectors like education, government, and private cloud.