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A new version of Proxmox Backup Server has been released.

Enterprise software developer Proxmox Server Solutions GmbH (henceforth "Proxmox") has today released version 2.4 of Proxmox Backup Server bringing dark mode for the web interface, LDAP authentication realm, and support for WORM tapes. The open-source server backup solution allows backing up and restoring VMs, containers, and physical hosts. By supporting incremental, fully deduplicated backups, it significantly reduces network load, required storage space and, as a result, total infrastructure cost. With the integrated web interface, users can easily manage and monitor all backup tasks from a single pane of glass and quickly recover single files, entire VMs, and archives in case of a disaster.

What’s new in Proxmox Backup Server 2.4

This version is based on Debian 11.6 “Bullseye”, but using a newer Linux kernel 5.15, and including ZFS 2.1.9. While the 5.15 kernel is the stable default, Linux kernel 6.2 can optionally be installed for better support of the latest hardware.

  • Dark Mode: The fully integrated theme “Proxmox Dark” is available for the web interface. By default, the prefers-color-scheme media query from the browser or operating system will be used to decide the default color scheme. Users can override the theme via a newly added Color Theme selector in the user menu.
  • Added LDAP authentication realm and user synchronization: This version now allows user authentication against an external LDAP server. In order to be able to log in, users in LDAP realms must be added manually. Alternatively, users can be synced automatically from the LDAP server. In the web interface the dialog Add User has a realm field, making it possible to manually add users to an LDAP or OpenID Connect realm.
  • WORM tapes: Initial support for WORM (write once, read many) tapes is available with version 2.4. With the special WORM cartridges, data can only be written to the memory once; subsequent changes are not possible. WORM compliant storage is often a requirement for organizations with legal regulations. In addition, it serves, for example, to protect against the accidental or intentional deletion of critical data. Proxmox Backup Server makes no distinction between normal and WORM tapes, so different naming schemes and dedicated media pools are recommended.

Further notable enhancements

  • Task logs can now be downloaded directly in the web interface as text files for further inspection.
  • Installation ISO: During installation, the UTC timezone can be selected, facilitating the synchronization of hosts or clusters that are distributed across multiple geographic locations.
  • The technical documentation has been further improved with more detailed explanations of the Garbage Collection (GC). Also, dark mode support for the docs and the API viewer widget has been added.

Proxmox Backup Server seamlessly integrates into Proxmox Virtual Environment – users just need to add the storage for the Proxmox Backup Server as a new storage backup target to Proxmox VE. The software is published under the GNU AGPL, v3 license.


Proxmox Backup Server is free and open-source software, published under the GNU AGPL, v3. The downloadable ISO image can be quickly installed on bare-metal using the installation wizard. The centrally managed software stack Proxmox Backup Server 2.4 is now available for download at

Distribution upgrades from older versions of Proxmox Backup Server are possible via APT. It is also possible to install Proxmox Backup Server on top of Debian.

For enterprise users, Proxmox Server Solutions GmbH offers a subscription-based support model, which provides access to the extensively tested Enterprise Repository, with regular updates via the web interface, as well as technical support on a subscription basis. Prices start at EUR 495 per server, including unlimited backup storage and unlimited backup-clients.