QUICK_REFERENCE

A quick reference for diagnosing common etcd problems in two-node OpenShift clusters with fencing. Etcd is the service that stores the cluster’s critical state, while fencing isolates a failed node.

In plain words
What is it for?
Use it to check Pacemaker and etcd health, list etcd members, collect diagnostics, and troubleshoot cluster virtual machines through Ansible.
Why use it?
It helps avoid checking the wrong machines and gathers the status and logs needed to identify cluster problems.

Command for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/openshift-eng/two-node-toolbox/quick_reference
Clone the repo
git clone --depth 1 https://github.com/openshift-eng/two-node-toolbox

Made for: Claude Code.

Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,657 The whole file, excluding the scripts and references it only reads on demand.
Security scan D 3 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.03657
Opus 5 $0.00000 $0.01828
Sonnet 5 $0.00000 $0.00731
Haiku 4.5 $0.00000 $0.00366

Measured yesterday against content hash 4bdf863350a5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade D, and why

QUICK_REFERENCE scanned grade D with 3 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

ansible cluster_vms -i deploy/openshift-clusters/inventory.ini -m shell -a "sudo pcs status" -b

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

"sudo rm -rf /var/lib/etcd/*" -b

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

"curl -k -u <user>:<pass> https://<bmc-ip>/redfish/v1/Systems" -b
.claude/commands/etcd/QUICK_REFERENCE.md · 403 lines

How it starts

The opening of the file, as written. The whole thing — 403 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Etcd TNF Quick Reference Guide

Fast troubleshooting for common etcd issues on Two-Node with Fencing clusters

Use this guide for quick diagnosis and remediation. For detailed analysis, refer to TROUBLESHOOTING_SKILL.md.


CRITICAL: Target the Correct Hosts

Always use cluster_vms host group for etcd/Pacemaker commands:

  • Correct: ansible cluster_vms -i inventory.ini -m shell -a "pcs status" -b
  • Wrong: ansible all -i inventory.ini ... (would include hypervisor)
  • Wrong: ansible hypervisor -i inventory.ini ... (hypervisor has no etcd)

The hypervisor is only for VM lifecycle (virsh/kcli). All etcd operations run on cluster_vms.


Quick Diagnostics

Collect all diagnostics automatically:

./helpers/etcd/collect-all-diagnostics.sh

Check cluster health quickly:

# Pacemaker status (on cluster VMs)
ansible cluster_vms -i deploy/openshift-clusters/inventory.ini -m shell -a "sudo pcs status" -b

# Etcd member list (on cluster VMs)
ansible cluster_vms -i deploy/openshift-clusters/inventory.ini -m shell -a "sudo podman exec etcd etcdctl member list -w table" -b

# OpenShift etcd operator (if cluster access available)
oc get co etcd -o yaml | grep -A10 "status:"

Check workload distribution during failover:

# Quick check: functional pods per node (uses simple grep)
oc get pods -owide -n <namespace> | grep Running | grep <node_name> | wc -l

# Detailed analysis: shows READY status to filter stale pod references
oc get pods -n <namespace> \
  -o custom-columns='NAME:.metadata.name,STATUS:.status.phase,READY:.status.conditions[?(@.type=="Ready")].status,NODE:.spec.nodeName'

# Count only functional workloads
oc get pods -n <namespace> \
  -o custom-columns='NAME:.metadata.name,STATUS:.status.phase,READY:.status.conditions[?(@.type=="Ready")].status,NODE:.spec.nodeName' \
  | grep 'True.<node_name>' | wc -l

💡 Key Insight: During failover scenarios, pod status can show stale references. Use READY=True filter or the simple grep approach to see actual functional workloads. STATUS=Running + READY=False indicates stale pod references from failed nodes.

Read the full file on GitHub · 403 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 403 lines · 0 tokens per session scan D 4bdf863350a5

Subscribe to this mod's changes

QUICK_REFERENCE is a command published in the GitHub repository openshift-eng/two-node-toolbox (5 stars, last pushed 28d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 3,657 tokens. A static security scan graded it D with 3 findings (asks for root, recursive force delete, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.