Zabbix Database Error: No such file or directory After unattended-upgrade
After unattended-upgrade automatically ran on one of my Zabbix servers, the Zabbix frontend started showing a confusing database error. When […]
Observability & Operations
Upgrade & Migration
Cloud, Linux & Virtualization
Add a New KVM Storage Pool and Move Existing VMs to It on Ubuntu 24.04
In a previous post, I showed how to set up KVM and Cockpit on Ubuntu 24.04. That setup works well
Cloud, Linux & Virtualization
Upgrade a Single-Node Ceph Squid (v19) cephadm Cluster to Tentacle (v20) on Ubuntu 24.04
…and switch from Ubuntu’s apt cephadm (v19) to a manually downloaded cephadm (v20) This post documents a practical, works-in-real-life upgrade
Identity, Security & PKI
Upgrade Keycloak (Tarball + systemd + MariaDB) on Ubuntu 24.04
Short outage method: Stop → Backup → Upgrade → Start Example upgrade: 26.4.6 → 26.5.2 This post upgrades a Keycloak
Identity, Security & PKI
Move HashiCorp Vault OSS to Another AWS EC2 Instance (Ubuntu 24.04, File Storage, AWS KMS Auto-Unseal)
This post shows how to move a single-node Vault OSS deployment from one EC2 instance to another existing EC2 host
Cloud, Linux & Virtualization
How to Move a KVM VM on Ubuntu 24.04 to VMware Workstation Pro on Windows (QCOW2 → VMDK)
This is the reverse of my previous migration (VMware Workstation → KVM). The safe, repeatable flow is: Shutdown the VM
Observability & Operations
Monitor Backstage with Grafana LGTM Stack using OpenTelemetry (Alloy OTLP → Mimir)
This post migrates Backstage backend monitoring from kube-prometheus-stack (ServiceMonitor + Prometheus scrape) to an LGTM-style push pipeline: Backstage (OpenTelemetry SDK)
Containers & Kubernetes
Upgrade a 3-Node kubeadm HA Kubernetes Cluster to v1.35.0 (kube-vip + MetalLB + Traefik) on Bare-Metal Ubuntu 24.04
This post shows how to upgrade a 3-node kubeadm cluster from Kubernetes v1.34.x → v1.35.0 on Ubuntu Server 24.04, where:
Networking & Connectivity
WireGuard Site-to-Site VPN: MikroTik hEX ↔ OPNsense 25.7 on AWS
This post upgrades the previous single-PC WireGuard client setup into a site-to-site VPN: Follow-up to: Architecture What changes vs “single
DevOps & Software Delivery
Migrate Backstage Docker Deployment from SQLite to PostgreSQL
This guide shows how to run a production-style Backstage container that uses PostgreSQL (instead of SQLite), with secrets provided through