EST. 2026 — Notes from real server work SYSADMIN · SECURITY · AI · DIRECTADMIN Issue 01
THE SYSADMIN ALMANAC
Home / Tags / Homelab
Homelab

#Homelab

7 articles
Hardware / IoT
Reading an Unknown Modbus Device: Verify Before Interpreting
Hardware

Reading an Unknown Modbus Device: Verify Before Interpreting

My notes on tracking down an undocumented device on an RS485 bus, from scanning baud rates and addresses one combination at a time to proving which registers hold live values and which are dead, and the lesson that guessing a device's type from number patterns alone can lead to months of misinterpretation.

#modbus#rs485#serial#iot
11 min read·14 Oct
Borrowing a VLAN for Windows Tools That Need the Same L2
Network

Borrowing a VLAN for Windows Tools That Need the Same L2

Many manufacturers' device discovery tools use broadcasts that cannot cross L3, so connecting over a VPN still leaves devices invisible. A solution that leaves switch ports alone is to put a small Windows VM on Proxmox with its interface directly in that VLAN, with pitfalls around vlan-aware bridges, a full thin pool breaking other VMs, and virtio leaving Windows without a network adapter after installation.

#proxmox#kvm#vlan#networking
8 min read·19 Sep
Control TP-Link Omada OC200 via REST API with Python
Network

Control TP-Link Omada OC200 via REST API with Python

A practical guide to logging into an OC200 controller through REST API v2 with Python — handling CSRF tokens, self-signed certs, fetching sites/devices/SSIDs/DHCP/port-forward rules, and writing back with PATCH, including the read-only fields that cause a nonzero errorCode

#omada#networking#api#python
8 min read·20 Jul
Reading a DTSU666 3-Phase Meter with Raspberry Pi over Modbus RS485
Linux

Reading a DTSU666 3-Phase Meter with Raspberry Pi over Modbus RS485

Notes on connecting a DTSU666 Smart Power Sensor to a Raspberry Pi over RS485, reading 3-phase electrical measurements from multiple meters using Modbus RTU, decoding 32-bit floats correctly, and storing them in SQLite/MySQL before exporting through MQTT and a REST API, including a negative-value bug I ran into myself

#modbus#rs485#iot#dtsu666
11 min read·19 Jul
Reading Modbus RTU over an RS485 Gateway Without Phantom Values
Linux

Reading Modbus RTU over an RS485 Gateway Without Phantom Values

Connecting multiple Modbus RTU meters/sensors on an RS485 bus through a serial-to-Ethernet gateway can produce phantom values, incorrect readings, or devices that do not actually exist — because a transparent gateway uses RTU-over-TCP, which requires assembling frames and calculating CRC yourself, and validating every reply. This article covers the rules I learned from doing it.

#modbus#rs485#iot#python
9 min read·15 Jul
Using Claude to Upgrade Proxmox 8 to 9 and Rebuild Windows VMs
Linux

Using Claude to Upgrade Proxmox 8 to 9 and Rebuild Windows VMs

A real case using VS Code + Claude to upgrade an entire Proxmox cluster from 8 to 9, then delete and rebuild all Windows VMs for VDI without ever SSHing into a host myself. I have laid out the commands and scripts Claude generated during the actual work as steps that a person or AI can read and run again.

#claude-code#ai#vscode#proxmox
13 min read·20 Jun
Build a Desktop AI Server with WSL2 + Ollama + OpenClaw
AI

Build a Desktop AI Server with WSL2 + Ollama + OpenClaw

A record of building a home AI server from scratch, starting with Windows 11 IoT, installing WSL2 + Ubuntu, setting up Ollama to run LLMs on two GPUs, then adding multiple OpenClaw instances through systemd, covering drivers, custom Modelfiles, user isolation, and benchmarks

#wsl2#ollama#openclaw#local-llm
18 min read·18 Feb