Proxmox has released Proxmox Backup Server 4.2, an open-source, enterprise-grade backup solution for virtual machines, containers, and physical hosts. This release is based on Debian 13.4 “Trixie” and includes Linux kernel 7.0 as the new stable default, along with ZFS 2.4.
The main update in version 4.2 is official support for S3-compatible object stores as a backup storage backend. S3-backed datastores now track request counts and traffic statistics, with counters appearing in the datastore summary.
Moreover, backup groups and namespaces can now be moved within the same datastore, allowing administrators to reorganize backups without manual recreation. Proxmox states that per-group locking is used during this process to maintain consistency.
Sync jobs have also been enhanced, with push sync jobs that can now encrypt snapshots in real time before sending them to remote datastores. Conversely, pull sync jobs can decrypt snapshots that were encrypted on remote datastores. Tape and sync encryption keys are now managed from a centralized panel.
Performance has been improved as well through concurrent group pull and push support. Sync jobs can now process multiple groups in parallel using the new worker-threads property, which Proxmox says improves throughput on high-latency networks and helps work around HTTP/2 connection limitations. Plus, logging for sync jobs has been improved with contextual prefixes and better visibility for push sync operations.
For more details, see the release announcement or visit the changelog.
Proxmox Backup Server 4.2 is now available as a downloadable ISO image for bare-metal installation. Existing installations can be upgraded using the standard APT package management system, and the software can also be installed on an existing Debian system.
