https://blogs.damiendye.uk/en/proxmox/ Recent content in Proxmox on Damien Dye's Blog Hugo en-GB Sun, 04 Oct 2026 10:30:00 +0100 https://blogs.damiendye.uk/en/proxmox/moving-an-oem-licence-into-a-proxmox-vm/ Sun, 04 Oct 2026 10:30:00 +0100 https://blogs.damiendye.uk/en/proxmox/moving-an-oem-licence-into-a-proxmox-vm/ How the OEM licence in a PC's firmware, the ACPI MSDM table, gets into a Proxmox VM: reading it, validating it before QEMU fixes up a broken one, storing it root-only in pmxcfs, and Microsoft's own terms on moving it, including one VM on the licensed machine and why volume licences never use it. https://blogs.damiendye.uk/en/proxmox/branding-a-proxmox-vm/ Sun, 04 Oct 2026 10:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/branding-a-proxmox-vm/ Five places a stock Proxmox VM shows somebody else's name, and how to replace each so apt cannot undo it: SMBIOS strings filled from the VM's own config, the SeaBIOS splash, a rebuilt OVMF logo or an option ROM that leaves the firmware alone, and the web UI logo, all read from source. https://blogs.damiendye.uk/en/proxmox/kvm-the-hypervisor-inside-proxmox-ve/ Wed, 12 Aug 2026 09:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/kvm-the-hypervisor-inside-proxmox-ve/ "Is Proxmox enterprise grade?" is a question about the hypervisor, and Proxmox VE does not contain one. The hypervisor is KVM, the same kernel module under EC2, Google Cloud, Nutanix AHV and OpenShift Virtualisation. What Proxmox actually maintains, why the type 1 argument aims at the wrong line, and what the shared foundation does not buy you. https://blogs.damiendye.uk/en/proxmox/hdd-backed-ceph-bcache-optane/ Fri, 07 Aug 2026 20:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/hdd-backed-ceph-bcache-optane/ Flash pricing has made all-NVMe hard to justify, and enterprise HDDs are worth another look. Acceptable latency out of them on hyper-converged Proxmox Ceph: move RocksDB off the spindle, pair each disk with its own Optane through bcache (Optane, because NAND endurance is wrong for the job), and be honest about the failure modes it buys. https://blogs.damiendye.uk/en/proxmox/licence-free-vdi-intel-arc-pro-sriov/ Fri, 07 Aug 2026 17:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/licence-free-vdi-intel-arc-pro-sriov/ Intel's Arc Pro cards do SR-IOV natively, with no vGPU licence to buy — which makes a licence-free Windows VDI on Proxmox genuinely possible. The whole build on a B50, the Windows-first bootstrap problem, why the firmware caps it at two virtual functions, and how many each card in the B-series gives you. https://blogs.damiendye.uk/en/proxmox/proxmox-routed-mesh-sdn-openfabric/ Fri, 07 Aug 2026 16:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/proxmox-routed-mesh-sdn-openfabric/ Three Proxmox nodes wired directly to each other in a triangle, with OpenFabric routing over the mesh and Ceph plus VXLAN client networks riding on top. Built entirely in the web interface, and honest about where the design stops scaling. https://blogs.damiendye.uk/en/proxmox/kernel-boot-flags-host-guest/ Fri, 07 Aug 2026 15:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/kernel-boot-flags-host-guest/ Most Proxmox tuning lines you find online are one blob of kernel flags. Half of them belong on the hypervisor, half belong inside the guest, two of the popular ones do nothing at all, and a few change meaning depending on which side of the boundary they land. https://blogs.damiendye.uk/en/proxmox/virtual-nvme-proxmox/ Fri, 07 Aug 2026 14:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/virtual-nvme-proxmox/ QEMU can emulate a real NVMe controller, so the guest uses its own in-box NVMe driver with no VirtIO media required. It is also unmigratable by design, invisible to Proxmox backups, and no faster than VirtIO SCSI. Here is how to add one and when it is worth it. https://blogs.damiendye.uk/en/proxmox/vm-time-ptp-kvm/ Fri, 07 Aug 2026 13:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/vm-time-ptp-kvm/ A virtual machine's clock is built on an assumption virtualisation breaks: that the CPU keeps counting. Why guest time drifts on every hypervisor, what the skew actually breaks — Kerberos, TLS, Ceph, Windows — and how ptp_kvm fixes it properly on QEMU/KVM. https://blogs.damiendye.uk/en/proxmox/block-sizes-4kn-512e/ Fri, 07 Aug 2026 12:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/block-sizes-4kn-512e/ 512e drives present 512-byte sectors they do not have, and the firmware makes up the difference on every unaligned write. What that costs on the medium, in the host and in write amplification — why direct synchronous writes are the worst case — and how to convert a fleet to 4Kn. https://blogs.damiendye.uk/en/proxmox/pcie-resizable-bar/ Fri, 07 Aug 2026 11:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/pcie-resizable-bar/ Resizable BAR lets the CPU map a GPU's whole framebuffer instead of peering at it through a 256MB window. Intel calls it required for Arc, NVIDIA enables it per game, AMD sells it as Smart Access Memory — and for AI work it changes the transfer, not the maths. https://blogs.damiendye.uk/en/proxmox/pcie-passthrough-performance-the-iommu-tax/ Fri, 07 Aug 2026 10:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/pcie-passthrough-performance-the-iommu-tax/ Why PCIe devices lose throughput when passed through to a VM via VFIO, and the practical tuning steps that claw most of it back. https://blogs.damiendye.uk/en/proxmox/numa-alignment-proxmox/ Fri, 07 Aug 2026 09:40:00 +0100 https://blogs.damiendye.uk/en/proxmox/numa-alignment-proxmox/ On multi-socket systems, a VM with its vCPUs on one NUMA node and its passed-through device on another loses 20–30% throughput before you've even looked at anything else. https://blogs.damiendye.uk/en/proxmox/pcie-aspm-passthrough/ Fri, 07 Aug 2026 09:20:00 +0100 https://blogs.damiendye.uk/en/proxmox/pcie-aspm-passthrough/ Active State Power Management saves a few watts on idle PCIe links. Under VFIO passthrough, it adds latency jitter that's hard to diagnose and easy to fix. https://blogs.damiendye.uk/en/proxmox/pcie-maxpayloadsize/ Fri, 07 Aug 2026 09:00:00 +0100 https://blogs.damiendye.uk/en/proxmox/pcie-maxpayloadsize/ QEMU's virtual root complex defaults to 128-byte TLP payloads. Most devices support 256 or 512. One kernel parameter fixes it. https://blogs.damiendye.uk/en/proxmox/q35-not-i440fx/ Fri, 07 Aug 2026 08:45:00 +0100 https://blogs.damiendye.uk/en/proxmox/q35-not-i440fx/ The two QEMU virtual chipsets are not interchangeable. Q35 provides a proper PCIe topology that passthrough, modern Windows, and the wider KVM ecosystem all depend on.