EC2 Kernel & Device Diagnostic Troubleshooter
Use the interactive troubleshooter below to identify your EC2 kernel or device error by symptom, review the raw error log, 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 | ENA Keep-alive watchdog timeout | Keep alive watchdog timeout | The ENA driver watchdog mechanism did not receive keep-alive messages in the preceding three seconds, concluding the device experienced a failure. | N/A |
| 2 | ENA Register read timeout | reading reg failed for timeout | Failures of memory mapped I/O (MMIO) read operations caused by an incompatible or incorrectly compiled driver, a busy hardware device, or hardware failure. | N/A |
| 3 | I/O error (block device failure) | end_request: I/O error | A failed Amazon EBS volume or a failed physical drive on an instance store-backed instance. | Terminate the instance and launch a new instance. |
| 4 | I/O ERROR: neither local nor remote disk | IO ERROR: neither local nor remote disk | A failed Amazon EBS volume or a failed physical drive. | Terminate the instance and launch a new instance. |
| 5 | request_module: runaway loop modprobe | runaway loop modprobe binfmt-464c | Using an unstable or old Linux kernel (for example, 2.6.16-xenU) can cause an interminable loop condition at startup. | Terminate the instance and launch a new instance, specifying the –kernel and –ramdisk parameters. |
| 6 | Kernel panic: "FATAL: kernel too old" | FATAL: kernel too old | An incompatible kernel and userland mismatch causing a system panic. | N/A |
| 7 | VFS: Unable to mount root fs on unknown-block | VFS: Unable to mount root fs on unknown-block(8,1) | A hardware device failure preventing the instance store-backed system from accessing the root filesystem. | Terminate the instance and launch a new instance using a modern kernel. |
| 8 | XENBUS: Timeout connecting to devices! | XENBUS: Timeout connecting to devices! | The block device is not connected to the instance, or the instance is using an old instance kernel. | N/A |