Shorts · Costin Ștefan

Multus CNI

Tue, 01 Sep 2026 00:00:00 +0000

Still the reference implementation for secondary interfaces on bare metal. The thing the docs bury: a NetworkAttachmentDefinition is namespaced, so a pod cannot reference one from another namespace. Every Multus problem I have debugged in the last year traced back to that one line.

A CNI meta-plugin for multi-homed pods in Kubernetes, attaching multiple network interfaces to a single pod.

etcd performance and tuning

Thu, 27 Aug 2026 00:00:00 +0000

Worth re-reading before blaming disks. Raft round-trip is bounded by fsync latency, and the number nobody watches is event count — 700k accumulated events will degrade a cluster long before the p99 write latency looks bad.

How disk and network latency bound etcd throughput, and the settings that matter when they do.

Cluster API Provider OpenStack

Mon, 24 Aug 2026 00:00:00 +0000

The CAPO reference I wish I had opened first. Read the flavor and image sections before you write a single manifest — a missing flavor fails late, during machine creation, and the error surfaces nowhere near the cause.

Reference documentation for declaring and managing Kubernetes clusters on OpenStack with Cluster API.

Flux components

Wed, 19 Aug 2026 00:00:00 +0000

The component breakdown is the page to hand someone who is new to Flux. Once you see that source-controller and kustomize-controller are separate reconcile loops, the “why has my change not landed” question answers itself.

The GitOps toolkit controllers that make up Flux, and how each one reconciles its part of the system.

Ceph common issues

Sat, 15 Aug 2026 00:00:00 +0000

Bookmarking for the mon quorum section. A crashing mon is usually not a Rook problem, it is Ceph telling you something through a crash report that Rook never surfaces — check ceph crash ls before touching the operator.

Diagnosing the failures that show up most often in a Rook-managed Ceph cluster.

Hardware transcoding

Tue, 11 Aug 2026 00:00:00 +0000

Set this up on the homelab box. The part that cost me an evening: hardware transcoding needs the container to see the device and the matching driver userspace inside the image. Host driver alone is not enough.

Configuring GPU-accelerated video transcoding in Immich, including per-vendor driver requirements.

PCI(e) passthrough

Thu, 06 Aug 2026 00:00:00 +0000

The canonical passthrough page. Still the fastest way to work out whether your IOMMU groups will cooperate before you buy hardware for a build.

Passing physical devices through to Proxmox guests, covering IOMMU setup and group isolation.

512KB Club

Thu, 30 Jul 2026 00:00:00 +0000

The reason this site has no web fonts and no framework. A budget is a much better design constraint than good intentions.

A collection of performance-focused websites whose total uncompressed page weight stays under 512KB.

Data templates

Wed, 22 Jul 2026 00:00:00 +0000

How this page is built — the whole feed is one YAML file walked by a template. No content files, no taxonomy, no build step beyond Hugo itself.

Reading structured YAML, JSON or TOML files from the data directory inside Hugo templates.