Notes
Operational knowledge, kept explicit.
Current runbooks, troubleshooting records and architecture notes. Legacy material is marked rather than silently presented as current practice.
Diagnosing deferred Mailcow delivery: local firewall or remote MX refusal?
A short evidence-driven workflow for distinguishing local SMTP connectivity problems from selective refusal by a remote mail server.
Monitoring Proxmox VE with Prometheus using API tokens and a trusted CA
A production-oriented pattern for collecting Proxmox metrics without disabling TLS verification or using a full administrator account.
Migrating Ceph authentication keys to aes256k without losing cluster access
A staged operational approach to rotating Ceph service and client keys while preserving quorum and administrative access.