Viennese virtualization veteran releases Proxmox VE 9 and Backup Server 4
Making a bit of a FOSS with Virtual Environment update
Viennese virtualization veteran Proxmox has updated its hypervisor and its storage offering to new, Debian 13 versions.
Austrian FOSS vendor Proxmox, which celebrates its 20th anniversary this year, has released new versions of its Debian-based hypervisor Proxmox Virtual Environment and its companion product Proxmox Backup Server. Both are based on Debian 13.
The release notes for Proxmox VE 9.0 form part of the product roadmap, but there is also a more discursive press release for the new version. Proxmox is built from several separate FOSS products, integrated and presented with a custom web management UI.
Debian is one of them, but it's not an unmodified version: the company changes the underlying Debian to add more features. In addition to Debian itself, Proxmox VE is built around the KVM hypervisor and the tools provided by QEMU 10.0.0.2. It can also run containers, via LXC 6.0.4, and handle storage clusters via Ceph "Squid" version 19.2.3.
While Debian 13 uses kernel 6.12, Proxmox ships a newer version – it comes with kernel 6.14. Proxmox also adds the ZFS filesystem to the kernel, and Proxmox VE 9 includes OpenZFS 2.3.3, which was released in June. We covered the release of OpenZFS 2.3 in January, describing maybe its most significant new feature: RAID expansion. This has been a long time coming – we covered it in February 2022. How it works is described in detail in the pull request, but it lets you enlarge RAID-Z arrays by adding a new drive. The array is then resized to include the additional space from the new drive, and it can be used normally while this is underway.
(It's significant that adding a new drive merely makes a bigger array of the same level: you can't transparently migrate between different RAID levels, or at least, not yet. If you have a RAID-Z2 array, meaning two parity drives – like conventional RAID level 6 – then after adding a drive, it will still be a RAID-Z2 with two parity drives, just a bigger one.)
Proxmox VE 9 isn't just a version update; it also has new features. VMs with thick-provisioned LVM storage – meaning that all the space of their virtual drives was allocated at once when they were created – now gain snapshot support, which is also supported on network storage accessed over iSCSI or Fibre Channel. The software-defined networking stack (SDN) now has Fabric support, meaning multiple redundant communications paths over multiple network ports and connections. Its High-Availability Cluster functionality now supports setting affinity values, meaning that you can tell the cluster which VMs should be kept close to others for the best performance. Its web UI is implemented in Rust using the Yew framework and now works better on mobile browsers.
Proxmox Backup Server 4.0 has release notes in its separate product roadmap. It's based on the same core OS as its bigger sibling: Debian 13, plus kernel 6.14 with added OpenZFS 2.3.3. This isn't a full NAS distro – there are plenty of those to choose from out there already. It shares the new RAID-expansion feature with its sibling product, but has some new tricks of its own as well. When a removable datastore is mounted, this version can be configured to automatically synchronize to the newly available volume.
It's a technology preview in version 4.0, but the Backup Server now also supports S3 storage. Originally an AWS offering – the name stood for Amazon Simple Storage Service – S3 is now a standard API and is also offered by other cloud providers as well, such as Hetzner Object Storage or Ionos Object Storage. It's an object store, rather than file- or disk-based. A Backup Server 4.0 box can now attach to S3 storage buckets and use them for holding backup data. The advantage of this is disaster recovery: although one Backup Server controls one S3 instance, should it fail, the backups won't be affected. You can just bring a new storage server instance online, and then retrieve the remote backups.
Upgrades from the existing version versions are supported and documented. Proxmox describes upgrading from VE 8.x to 9, including a list of known issues, and also how to upgrade from Backup Server 3.x to 4.
Downloads of ISO installation media for both products are available now. It's also possible to install the Proxmox VE hypervisor and tools on top of an existing instance of Debian, for instance if you want to do custom disk partitioning. The company also has documentation covering installing Proxmox VE on Debian 13. ®