EC2 OS/Kernel Symptom Diagnostic Troubleshooter (Part 5)
Use the interactive troubleshooter below to identify your EC2 OS/kernel symptom, review the raw evidence, understand the root cause, and apply the recommended fix.
🚨 Step 1: What specific error symptom are you experiencing?
Please click the most accurate description:
Quick Reference Table
| # | Scenario | Key Error Signal | Root Cause | The Fix |
|---|---|---|---|---|
| 1 | Unreachable instance requiring manual kernel panic / crash dump via Nitro diagnostic interrupt | kernel.unknown_nmi_panic sysctl parameter missing or unset | The Linux kernel does not automatically trigger a panic when receiving an unknown non-maskable interrupt (NMI) from the Nitro hypervisor unless explicitly configured. | Add kernel.unknown_nmi_panic=1 to /etc/sysctl.conf and reserve memory via boot parameters (e.g., crashkernel=160M). |
| 2 | Processor benchmarking routines experiencing latency / delays | cpupower idle-info | grep "Number of idle states:" | Temporarily idle CPU cores enter a sleep state (C-state) to save power, causing a latency delay when the core is called to resume processing. | for i in \seq 1 $((N-1))`; do cpupower idle-set -d $i; done` |
| 3 | Network interface attachment failures on Nitro instances (e.g., C6i, C6gn) | N/A | The instance is running an outdated ENA driver (earlier than version 1.2) which is incompatible with the Nitro networking hardware. | Ensure the instance has ENA driver version 2.2.9 or later installed. |