Amazon EC2实例仅通过1/2状态检查，SSH连接超时求助

Hey there, let's work through this issue together. The critical error you're seeing in the system log—Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,1)—tells us the kernel can't locate the root filesystem, which is why your instance is failing status checks and you can't SSH in. Here's how to fix this:

1. Check AMI and Instance Type Compatibility #

• The most common cause here is a mismatch between the AMI's architecture and your instance type. For example:
  • ARM-based AMIs (built for Graviton instances) won't run on x86_64 instances, and vice versa.
  • Some older AMIs only support specific instance families (e.g., older PV-based AMIs don't work with modern HVM-only instance types like t3 or m5).
• Quick test: Launch a new instance using an AWS official AMI (like Amazon Linux 2 or Ubuntu Server from the "Quick Start" section in the EC2 console). If this instance passes all status checks and you can SSH into it, the problem is definitely with your original public AMI.

2. Verify Virtualization Type #

• AWS EC2 supports two virtualization modes: Paravirtual (PV) and Hardware Virtual Machine (HVM). Most modern instances only support HVM, while some older AMIs are built for PV.
• When launching your instance, check the AMI's details (in the EC2 console, go to AMIs > select your AMI > Description tab) to see its virtualization type. Make sure your chosen instance type supports that mode.
• If your AMI is PV-only, try an older instance type that still supports PV (like t2.micro, though note PV is deprecated for most new instances).

3. Inspect Root Volume Configuration #

• Sometimes, even when using an AMI, the root volume might fail to attach correctly.
• Go to the EC2 console > Volumes, find the root volume attached to your problematic instance, and check its status. It should show "in-use" with no errors.
• When recreating the instance, avoid customizing the root volume settings (like changing size or type) unless necessary—stick with the AMI's default volume configuration first.

4. Rule Out AMI Corruption #

• If you're using a third-party public AMI, it's possible the image itself is corrupted or misconfigured.
• Check the AMI's community feedback (if available) to see if other users have reported similar issues.
• If you need to use this specific AMI, reach out to the AMI publisher for support, or try reimporting/relocating the AMI if you have access to its source.

Final Notes #

• The SSH timeout is a side effect of the instance failing to boot properly—fixing the kernel panic and status check failure will resolve the SSH issue.
• Restarting the instance won't fix this because the problem is with the boot configuration/AMI, not a temporary glitch.

内容的提问来源于stack exchange，提问作者skannan4