Proxmox Backup Server 2.1 released


VIENNA, Austria – November 23, 2021 – Enterprise software developer Proxmox Server Solutions GmbH (henceforth "Proxmox") has today announced version 2.1 of its open-source server backup solution. Proxmox Backup Server is based on Debian 11.1 “Bullseye”, but using the newer Linux kernel 5.13, and including OpenZFS 2.1. The whole software stack is written in Rust – a modern, fast, and memory-efficient language. The enterprise backup solution, capable of backing up and restoring VMs, containers, and physical hosts, supports incremental, fully deduplicated backups, significantly reducing network load, required storage space and, as a result, total cost of infrastructure.

What's new in Proxmox Backup Server 2.1

Improvements in Backup Management:

  • This version includes support for setting flexible traffic-control bandwidth limits. It enables the limiting of incoming (for example, backup) and outgoing (for example, restore) traffic from a set of networks. Users can now configure traffic control rules and set the limits to only apply during specific time-frames.
  • Protected backups: Backups can now be marked as “protected”, which will prevent them from being pruned or manually removed, without first removing the protected flag.
  • ‘group-filter’ for sync jobs and tape-backup jobs: For each backup job, multiple, cumulative filters can be applied: Users can specify if they want to process only a specific backup type (ct, vm, host), a specific group, or a regex that matches the group-ID for such a job.

Improved Round-Robin Database (RRD): The RRD system has been optimized. It allows for storing and displaying time-series data. A much higher resolution in the dashboard is now possible with the following intervals; per-day: 1 min / per-month: 30 min / per-year: 6h / per-decade: 1 week. In total, data can be retained for 10 years. The database uses a journal, in order to avoid data loss.

Improved Support for OpenID Connect (OIDC): This version brings improved support for the open protocol standard OpenID Connect, which provides Single Sign-On (SSO). The improved OIDC integration in Proxmox Backup Server supports configuring an arbitrary username claim. The requested scopes for user information requests can now also be set, however, the default settings remain the same (‘profile’ and ‘email’). The prompt behavior, which was previously hard-coded to ‘login’, is now unset and can be configured to the variants defined in the OIDC specification or an arbitrary extension.

Enhancements to the Web Interface:

  • A new traffic-control management panel is available in the GUI;
  • Load and usage graphs have much higher resolution;
  • For tape backup jobs, the next tape media label is now displayed;
  • Improved translations for Arabic, Basque, Brazilian Portuguese, French, German, Simplified Chinese, Traditional Chinese, Turkish.

Enhancements in the Backend: A new debugging tool, proxmox-backup-debug, has been added, which can be used to inspect Proxmox Backup datastore files, verify the integrity of chunks, and in some cases, recover data.


Proxmox Backup Server is free and open-source software, published under the GNU AGPL, v3. The downloadable ISO image can be installed on bare-metal. The centrally managed software stack can be quickly installed using the installation wizard. Proxmox Backup Server 2.1 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 449 per server, including unlimited backup storage and unlimited backup-clients.

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About Proxmox Backup Server
Proxmox Backup Server is an enterprise backup solution for backing up and restoring virtual machines, containers, and physical hosts. The open-source client-server software supports incremental backups, deduplication, Zstandard compression, and authenticated encryption. To increase productivity, the easy-to-use Proxmox Backup Server allows you to back up your data in a space-efficient manner, restore VMs, archives or single objects in a flash. With the web-based user interface, you can effectively reduce work hours thanks to simplified management. Proxmox Backup Server is licensed under the GNU AGPL, v3. Enterprise support subscriptions are available from Proxmox.

About Proxmox Server Solutions
Proxmox is a provider of powerful, yet easy-to-use open-source server software. Enterprises, regardless of size, sector or industry use the stable, secure, and scalable Proxmox solutions to deploy efficient, agile and simplified IT infrastructures, minimize total cost of ownership, and avoid vendor lock-in. Proxmox also offers commercial support and training services to ensure business continuity to its customers. Proxmox Server Solutions GmbH was established in 2005 and is headquartered in Vienna, Austria.