Dutch Proxmox Day 2025 wrap-up

On Thursday, September the 25’th in 2025, we opened the doors of Hotel Belmont in Lunteren. Figuratively speaking obviously, the hotel had already taken care of quite a few of our international guests for our main event of the year:

The Dutch Proxmox Day 2025

This time, with around 300 visitors, almost two times as big as the 2024 edition. The most noticeable differences with the last edition were the location and the fact that the 2025 edition was completely in English. This gave international visitors the possibility to attend and actually understand what we were talking about. And they responded: we’ve seen people from Germany, Belgium, Austria, France, Malta, Turkey and even Canada! You can imagine how proud we are that we’ve created an event with such interest.

After Ronald Otto (CEO Tuxis) opened the day at 10.00, Aaron Lauterer from Proxmox took the stage. He introduced Proxmox to the audience, and gave insight in the history of the company. He also took us through both the latest released features, as well as the planned features of PVE9, PBS4, PMG and the new Proxmox Data Center Manager.

He then taught us how we can identify packages on our Proxmox system as ‘Proxmox managed’ or ‘Debian managed’. And he took us through some history of Proxmox’ contribution to Open Source. For instance, did you know that the backup function in Qemu, used by a lot of other hypervisors too, originates at the Proxmox Offices in Vienna?

As Proxmox is fully open source, and there are no different feature sets, Aaron also invited people in the audience to contribute to Proxmox. Even though it maybe scary to sent your patches on a public mailing list, your code may just as well end up in Proxmox!

Rob Turk, Veeam

Veeam, also one of the sponsors for this Proxmox Day, started by introducing Veeam. As a rather new and very welcome addition to the Proxmox Ecosystem, not all visitors have a clear picture of what Veeam is and where it came from. Apparently, as we’ve learned, Veeam wasn’t about backups when it started. It was about monitoring and reporting. A skill they haven’t lost as Rob showed us some very nice monitoring and reporting features on backups that can be made of Proxmox hypervisors.

After the introduction he explained what a typical Veeam setup looks like and what you need to make sure that you have good and consistent backups. He also showed us how Veeam can help you implement your 3-2-1 backup strategy.

One of the things Rob really wanted to empathize was that Veeam says “We’re just getting started!”. The first release of Veeam with support for the Proxmox Hypervisor is around since august 2024 and they’re very committed to extending the feature set on this function. So keep an eye on the release notes!

Something especially interesting for visitors that are currently using Veeam with VMWare, was the matrix with all the supported hypervisors that Rob showed. This allows VMWare users to move from VMWare to Proxmox, using their Veeam backups.

Mark Schouten, Tuxis

As the organizing party, we took the liberty to present something ourselves too! I showed the audience how our collection of Proxmox Backup Servers is constantly growing, both in the Netherlands and abroad. I also wanted to share what we’ve learned so far in term of PBS and disk performance. As we use ZFS as the underlying storage layer, I tested and graphed the usefulness of the L2ARC, SLOG and Special devices-features in ZFS. As it turns out, only the Special Devices seem to add real performance to your backup server!

I then took the audience on a real life experience with Proxmox Support and `The Power of Open Source`, where one of my engineers and Proxmox Support dove into the deep and dark dungeons of the Linux kernel to debug which commit broke the hotplug-capabilities of our Western Digital hard disks. As it turned out, the Proxmox developers and developers from Western Digital found the culprit in the firmware of the Western Digital disk. And as we speak, Western Digital is shipping disks with the new firmware!

Alexander Wirt, credativ

As Proxmox is gaining popularity, the ecosystem of software around Proxmox is growing as well. Companies like credative have the possibility to create software themselves, building on top of or next to products like Proxmox. Alexander showed us how credative has built ProxLB and what the tool can do.

Even though Proxmox is a complete product, it might lack some features that one might want to add. ProxLB is such a tool and enables the user to automatically load balance VMs over your cluster, or to handle (anti-)affinity. Using some very simple YAML-configuration, one can distribute load evenly over your cluster, or even take a cluster node out of production to do maintenance.

More features like Power Management (empty & shutdown nodes if possible) and even more complicated Resource Scheduling are on the roadmap. There was one warning, don’t try to mix Proxmox HA Groups and ProxLB, as they don’t play together nicely.

As Tuxis, we wanted to show the visitors the extremely high quality and stability that Proxmox offers. And while we could talk for hours about how we do that, we thought that two more extreme users would be way better at that. That is why we invited the International Polar Foundation and the European Space Agency. They are running (or planning) to run Proxmox on locations where the costs of issues run into 6 figures, and fast.

Robbe van Herck, IPF

Think of a place very far away, and very cold. Then, reconsider and go even colder and further away. That is where Robbe is managing a Proxmox Cluster; at the Princess Elisabeth Station on Artartica. Proxmox is literally taking care of the vital services on the station, and Robbe told us about the stuff you run into when doing so.

For instance, LightOutManagement firmware that complains about sub-zero inlet temperatures. Or how to handle a cluster with three possible powerfeeds, each of which might fail at any time. How do you choose where to connect the PSU’s to?

But also, how much bandwidth do you have? There’s no fibre connectivity there, so satellites are your only option. But how many internet-connectivity-serving-satellites are there flying over the South Pole?

And if you have stuff up and running, but you’re missing a part. It might just as well take a year before the next shipment arrives. 

Han Wessels, ESA 

Even though Robbe (IPF) wins in terms of distance to his cluster. In theory, it’s easier to get there than where Han is going to run Proxmox, the Columbus module on the ISS. Han told us about the challenges you meet when you want to shoot gear up into space. Newer isn’t better in space tech, if proven hardware from the 60’s suffices, there’s no need to send up newer hardware that has only been tested on earth. Hardware needs to withstand the immense vibrations of a launch, the radiations that we (on earth) all get protected from by the atmosphere and the lack of air for cooling. Did you know that SSD-chips just start dying after about 9 months in space? Something you really need to take into account when selecting and testing your setup.

He demonstrated to us that cooling servers in space is a rather complicated matter since the heat must be disposed of outside of the station, which rules out traditional air cooling.

The ISS, where Proxmox will be handling all the data storage and transmission back to earth, has a cooling system but it is limited, as is the amount of available power. So choosing which hardware you can use is a pickle. Luckily, ESA and their team managed to get the gear in order and approved. And in June 2026, Proxmox will be running in space! Keep an eye on Space Mission NG-24 to see Proxmox going up into space!

After all these presentations, we had a great meetup with all the enthusiastic visitors and (soon to be) Proxmox users from the Netherlands and abroad. They all deserved their Goody Bag and Proxmox shirts!

We want to thank all the presentors, visitors and all the staff at Hotel Belmont! And a special thanks to our sponsors:

• Proxmox Server Solutions

• c’t Magazine

• Veeam Software

• KPN