Case Studies & Change Control
Structured documentation of operational experiences for learning, reflection, and sharing.
Purpose
This directory consolidates all change control and incident documentation:
-
Case studies for learning and teaching
-
Audit trail for compliance and tracking
-
Knowledge base of solved problems
-
Portfolio of operational experience
Directory Structure
case-studies/
├── tac/ # Vendor TAC cases (Cisco, Microsoft, etc.)
├── incidents/ # Incident reports (INC-*)
├── changes/ # Change requests (CR-*)
├── rca/ # Root cause analysis (RCA-*)
├── deployments/ # Major deployment records (DEPLOY-*)
├── templates/ # Templates for new entries
└── diagrams/ # D2/Mermaid source filesCategories
TAC Cases
Vendor technical support engagements with full diagnostic data.
| Case | Description | Status |
|---|---|---|
~500 endpoint auth failures, RabbitMQ 109% CPU on MNT |
RESOLVED |
Incidents
Unplanned outages and service disruptions.
| Incident | Description | Status |
|---|---|---|
Z Fold 7 Termux gopass/SSH not working |
OPEN |
|
Strongline gateway VLAN assignment issue |
IN PROGRESS |
|
ISE incident defense prep for leadership |
COMPLETE |
|
Vault backup failure due to SELinux context |
RESOLVED |
Change Requests
Planned modifications to production systems.
| CR | Description | Status |
|---|---|---|
Make nvim-domus configuration public |
COMPLETE |
|
Hyprland rice DJ mode configuration |
IN PROGRESS |
|
P50 migration from Arch Linux to Ubuntu 25.10 |
IN PROGRESS |
|
Arch Linux system upgrade (modestus-razer) |
APPROVED |
|
SELinux policy update for Vault backups |
COMPLETE |
Root Cause Analysis
Deep-dive analysis of significant incidents.
| RCA | Description | Status |
|---|---|---|
SSH config Host order precedence issue |
COMPLETE |
|
802.1X EAP-TLS CA chain verification failure |
COMPLETE |
|
WiFi EAP-TLS DHCP failure due to VLAN mismatch |
COMPLETE |
Deployments
Major system deployments and migrations.
| Deployment | Description | Status |
|---|---|---|
VyOS HA migration - pfSense to VyOS with VRRP failover |
COMPLETE |
|
k3s Kubernetes with Cilium, Vault Agent, SELinux |
COMPLETE |
|
Vault PKI platform → 3-node Raft HA cluster |
COMPLETE |
|
FreeIPA IdM (LDAP/Kerberos without integrated DNS) |
COMPLETE |
|
BIND DNS HA with bind-01/bind-02 replication |
COMPLETE |
|
Linux AD authentication for Xianming Ding workstation |
COMPLETE |
Templates
Use these templates to create new entries:
| Type | Template | When to Use |
|---|---|---|
TAC Case |
Opening vendor support case |
|
Incident |
Unplanned outage or service degradation |
|
RCA |
Post-incident root cause analysis |
|
Project |
Planned project or deployment |
Quick Create
# Create new incident
cp templates/incident-template.adoc incidents/INC-$(date +%Y-%m-%d)-<slug>.adoc
# Create new change request
cp templates/project-template.adoc changes/CR-$(date +%Y-%m-%d)-<slug>.adoc
# Create new TAC case
cp templates/tac-case-template.adoc tac/TAC-$(date +%Y-%m-%d)-<slug>.adoc
# Create new RCA
cp templates/rca-template.adoc rca/RCA-$(date +%Y-%m-%d)-<slug>.adocNaming Convention
| Prefix | Format | Example |
|---|---|---|
TAC |
|
|
INC |
|
|
CR |
|
|
RCA |
|
|
DEPLOY |
|
|
Statistics
| Category | Count |
|---|---|
TAC Cases |
1 |
Incidents |
7 |
Change Requests |
32 |
RCA |
10 |
Deployments |
7 |
Last updated: 2026-04-01
Work vs Personal
Cases can be tagged in their metadata:
:context: work // CHLA, professional
:context: personal // Domus Digitalis, home infrastructureThis enables filtering and separate case study views.