🚀 SNO Quick Tips & Commands

Essential commands for Single Node OpenShift installation and troubleshooting

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🔧 Fix: Live Environment Out of Space

If the SNO node is running from PXE/live environment and shows root filesystem at 100%, you need to remount with more space before coreos-installer can run.

Quick Fix

# On SNO node - remount /run with more space
sudo mount -o remount,size=8G /run

# Verify
df -h /run

# Now install RHCOS to disk
sudo coreos-installer install /dev/sda \
  --ignition-url http://10.0.10.191:8000/ignition/master-sno.ign \
  --insecure-ignition

# After installation completes, reboot
sudo reboot
Note: Use --insecure-ignition when fetching ignition over HTTP. For HTTPS, you can omit this flag or use --ignition-hash instead.

📊 Track Bootstrap Progress

On SNO Node

# SSH to SNO node
ssh core@10.0.10.103

# Watch bootkube service (main bootstrap service)
sudo journalctl -u bootkube.service -f

# Check bootkube status
sudo systemctl status bootkube.service

# Watch containers starting
watch -n 5 'sudo crictl ps | wc -l'

# List all running containers
sudo crictl ps

# Check kubelet status
sudo systemctl status kubelet

# Follow kubelet logs
sudo journalctl -u kubelet -f

From Bastion (Recommended)

# Set kubeconfig
export KUBECONFIG=~/workdir-ocp4-ai/auth/kubeconfig

# Watch cluster operators
watch -n 10 'oc get co'

# Watch nodes
watch -n 10 'oc get nodes'

# Use openshift-install to monitor
cd ~/workdir-ocp4-ai
openshift-install wait-for install-complete --log-level=info

⏱️ Bootstrap Timeline

0-5 minutes: Node boots, kubelet starts, bootkube service begins
5-15 minutes: Static pods start (etcd, API server, controller manager)
15-25 minutes: API server becomes available, cluster operators start deploying
25-40 minutes: All cluster operators become available
40-60 minutes: Installation complete ✅

✅ Quick Status Check

One-Liner Status Check

# From bastion
export KUBECONFIG=~/workdir-ocp4-ai/auth/kubeconfig
oc get clusterversion && oc get nodes && oc get co

Status Check Script

#!/bin/bash
# Save as check-sno-status.sh on bastion
export KUBECONFIG=~/workdir-ocp4-ai/auth/kubeconfig

echo "=== SNO Installation Status ==="
echo ""
echo "Node Status:"
oc get nodes 2>/dev/null || echo "  API not ready yet"
echo ""
echo "Cluster Operators:"
oc get co 2>/dev/null | head -10 || echo "  API not ready yet"
echo ""
echo "Cluster Version:"
oc get clusterversion 2>/dev/null || echo "  API not ready yet"
# Make it executable and run
chmod +x check-sno-status.sh
watch -n 30 ./check-sno-status.sh

🎯 Key Milestones to Watch

On SNO Node

# 1. Check if bootkube started
sudo journalctl -u bootkube.service | grep "bootkube.service: Started"

# 2. Check if static pods are running
sudo crictl ps | grep -E "etcd|kube-apiserver|kube-controller"

# 3. Check if bootstrap completed
sudo journalctl -u bootkube.service | grep -i "bootstrap complete"

From Bastion

export KUBECONFIG=~/workdir-ocp4-ai/auth/kubeconfig

# 1. Check if API server is accessible
oc version

# 2. Check if node appears
oc get nodes

# 3. Check cluster operators progress
oc get co

# 4. Check if all operators are available
oc get co | grep -v "True.*False.*False"

🔍 Verify Installation Success

Installation is complete when you see:
  • ✅ oc get nodes shows node as "Ready"
  • ✅ oc get co shows all operators "Available=True, Progressing=False, Degraded=False"
  • ✅ oc get clusterversion shows "AVAILABLE=True"
  • ✅ Console URL is accessible
  • ✅ Can login with kubeadmin credentials

Access the Cluster

# Get console URL
oc whoami --show-console

# Get kubeadmin password
cat ~/workdir-ocp4-ai/auth/kubeadmin-password

# Login via CLI
oc login -u kubeadmin -p $(cat ~/workdir-ocp4-ai/auth/kubeadmin-password)

⚠️ Common Issues & Quick Fixes

Issue: API Server Not Responding

# Check if API server pod is running
ssh core@10.0.10.103
sudo crictl ps | grep kube-apiserver

# Check API server logs
sudo crictl logs $(sudo crictl ps | grep kube-apiserver | awk '{print $1}')

Issue: Node Not Ready

# Check node conditions
oc describe node | grep -A 10 Conditions

# Check kubelet on node
ssh core@10.0.10.103
sudo systemctl status kubelet
sudo journalctl -u kubelet -n 50

Issue: Cluster Operators Degraded

# Find degraded operators
oc get co | grep -v "True.*False.*False"

# Get details on specific operator
oc describe co 

# Check operator pods
oc get pods -n openshift-

💡 Useful Aliases

Add these to your ~/.bashrc on the bastion for quick access:

# Add to ~/.bashrc
export KUBECONFIG=~/workdir-ocp4-ai/auth/kubeconfig

# Quick aliases
alias sno-ssh='ssh core@10.0.10.103'
alias sno-status='oc get nodes && oc get co'
alias sno-watch='watch -n 10 "oc get nodes && echo && oc get co"'
alias sno-logs='ssh core@10.0.10.103 "sudo journalctl -u bootkube.service -f"'
alias sno-pods='oc get pods -A'

# Then reload
source ~/.bashrc

📚 Related Documentation