OpenDJ: Find the JVM’s Default Heap and Right-Size It for Tiny Directories
TL;DR: Use jcmd to see what heap Java chose by default. For a tiny directory (~10 entries), set -Xms128m -Xmx128m […]
OpenDJ
Hands-On DevOps & Homelab Experiments
From Kubernetes and Ceph to Proxmox, Kafka, Jenkins, Vault, Android, and CI/CD, every guide here is a tested, step-by-step walkthrough from my lab.
OpenLDAP
Upgrade OpenDJ 4.9.4 → 4.10.2 on Ubuntu 24.04
Scope: In-place upgrade of a single OpenDJ node installed via the official .deb. No topology or port changes. Prerequisite: You
AWS, Zabbix
Monitor AWS with Zabbix 7.4 (AWS by HTTP): CloudShell-only IAM, Host Wizard, and Cost Explorer
Zabbix 7.4 includes AWS by HTTP templates. You create a single account host (e.g., aws-prod) and link only the base
OPNsense, Zabbix
Monitor OPNsense with Zabbix (Active Agent, GUI-only)
TL;DR Install the OPNsense Zabbix Agent plugin → enable it → set Hostname to exactly your Zabbix host name →
Zabbix
Convert “FreeBSD by Zabbix agent” to Active (Zabbix 7.4)
TL;DR Clone FreeBSD by Zabbix agent → mass-update all Zabbix agent items to Zabbix agent (active) → switch agent-based discovery
Ceph
Ceph RGW multisite UI: A Geo-Distributed File Browser for Your Object Storage
TL;DR: A file-browser style UI for Ceph RGW multisite that lets you browse, preview, and fetch objects across zones as
BIND, OPNsense
Custom DDNS for Your Home Lab with OPNsense BIND (Python + cron)
TL;DR: This guide shows a small Python script that discovers your public IPv4, updates an A record in the OPNsense
OPNsense
Using the OPNsense API with Python
The OPNsense firewall exposes a REST API for automation and integration. This post shows how to use the API from
Zabbix
Zabbix Agent Active vs Passive: What They Mean and When to Use Each
TL;DR How Active Works How Passive Works Quick Comparison Aspect Active Passive Connection Agent → Server :10051 Server → Agent
Ceph, KVM
Create a KVM VM on Ceph RBD
This follow-up shows the cleanest, minimal path to put a Libvirt/QEMU VM disk on Ceph RBD and create the VM