Nvme on Damien Dye's Blog https://blogs.damiendye.uk/en/tags/nvme/ Recent content in Nvme on Damien Dye's Blog Hugo en-GB Thu, 13 Aug 2026 09:00:00 +0100 Tri-Mode Adapters Buy Flexibility With Your NVMe Queues https://blogs.damiendye.uk/en/hardware/tri-mode-adapters-nvme-as-sas/ Thu, 13 Aug 2026 09:00:00 +0100 https://blogs.damiendye.uk/en/hardware/tri-mode-adapters-nvme-as-sas/ A tri-mode adapter lets any bay take SAS, SATA or NVMe, which is why U.3 backplanes exist. What it hides: your NVMe drives arrive in Linux as SCSI disks on mpt3sas, queue depth 128, sharing one tag pool and one x8 uplink. Two Gen4 drives saturate the card, one Gen5 is already past it. Whether the trade still makes sense in 2026. Making HDD-Backed Proxmox Ceph Clusters Fast — NVMe Metadata, One Optane Per Spindle, and What It Costs 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. A Virtual NVMe Device in Proxmox — and the Three Things You Give Up 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. 4Kn, 512e and 512n — Why Native 4K Wins, and What the Emulation Costs 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. PCIe Passthrough Performance on Proxmox VE — The IOMMU Tax and How to Minimise It 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.