A day after releasing Proxmox Virtual Environment 9.0, Proxmox Server Solutions GmbH has just unveiled its Backup Server 4.0, an open-source, enterprise-grade backup solution specifically designed for backing up VMs, containers, and physical hosts, built upon Debian 13 “Trixie.”
One of the standout features in this new release is native support for S3-compatible object storage, so users can seamlessly integrate Proxmox Backup Server with scalable and budget-friendly cloud solutions.
By leveraging local caching to minimize API calls, the system efficiently manages backup metadata and frequently accessed data chunks, optimizing performance and lowering costs. Additionally, backups remain accessible even if the primary server instance goes offline, significantly boosting disaster recovery capabilities.
Version 4.0 also introduces Live RAIDZ expansion through ZFS 2.3.3, allowing administrators to expand their storage pools without extensive downtime dynamically. In other words, you can now incrementally add drives directly into existing RAIDZ virtual devices, making storage expansion both cost-effective and convenient.
Further simplifying backup automation, Proxmox Backup Server 4.0 introduces automatic synchronization jobs for removable datastores. The new “run-on-mount” feature allows synchronization to start automatically whenever a removable datastore is mounted, greatly reducing manual effort and enhancing reliability.
As usual, Proxmox Backup Server integrates seamlessly with Proxmox Virtual Environment, allowing easy addition of backup storage targets within Proxmox VE.
For more details, check out the release announcement or the full changelog, which includes a complete list of changes.
The new version is now available for download as an ISO image, with easy installation via ISO on bare-metal hardware. Upgrades from version 3.x are fully supported, and comprehensive migration documentation is provided.
