EC2 Hypervisor / Hardware / Scheduled Event Diagnostic Troubleshooter (Part 1)
Use the interactive troubleshooter below to identify your EC2 hypervisor, hardware, or scheduled event 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 | xen — Capped average I/O size due to missing indirect descriptors support | kernel /boot/vmlinuz-4.9.20-11.31.amzn1.x86_64 ... xen_blkfront.max_indirect_segments=256 | The default kernel or instance may lack support for indirect descriptors, capping average I/O size to 44 KiB and limiting throughput. | Append xen_blkfront.max_indirect_segments=256 (or xen_blkfront.max=256 for older kernels) to the GRUB config and reboot. |
| 2 | NUMA — Invalid NUMA socket detected during DPDK ENA probe | EAL: Detected 1 NUMA nodes / EAL: Invalid NUMA socket, default to 0 | The DPDK environment abstraction layer (EAL) detects an invalid NUMA socket during PCI driver probing for the ENA adapter. | N/A |
| 3 | scheduled event / system-reboot — Instance scheduled for a reboot | "Code": "system-reboot" / "Description": "The instance is scheduled for a reboot" | AWS scheduled the underlying host for a system reboot to install updates or maintain the host. | Use aws ec2 modify-instance-event-window --instance-event-window-id <id> --time-range ... to reschedule the event. |
| 4 | scheduled event / instance-retirement — Instance running on degraded hardware | "Code": "instance-stop" / "Description": "The instance is running on degraded hardware" | AWS detected an irreparable failure of the underlying hardware that hosts the instance, triggering a scheduled retirement. | Stop and start the instance to migrate it to a new host (EBS-backed), or launch a replacement from an AMI (instance store-backed). |