Instance Change results in Instance reachability check failed

The instance probably needs rebooted, but for windows this can cause issues if not shut down from the OS side. Here are the troubleshooting steps for that error in case rebooting does not solve the issue: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-console.html

Hello,

Thank you for positing the use case. I will be happy to assist you today.

This outcome been experienced is expected as you are changing from an HVM instance type family T2 to a Nitro Instance family. The drivers requirements varies hence, before making the change You must install the necessary drivers required for Nitro Instances like c6i.large to run.

To resolve the issue, perform the following actions below:

1. Change the Instance back to t2.medium and start it

2. Once in Running state, Connect to the Instance via RDP

3. Install the following latest Drivers

   • Install ENA drivers (This is required for Networking) on the Instance. Follow the steps on the Documentation to install it. Install and upgrade ENA

   • Install NVMe drivers (This is required for EBS storage volume performance) on the Instance. See Upgrade AWS NVMe drivers

   • Update the EC2 Launch on the Instance Update EC2Config and EC2Launch

4. Go ahead to Stop the Instance and Change the Instance type to c6i.large. See the guideline to change Instance type Change the instance type of an existing instance

5. It should pass health and status check now.

Note that t2.medium Instances uses PV drivers for Networking and Storage while c6i.large Instance uses ENA for networking, NVMe for Storage.

Further reading on the Instances types -

Compute optimized instances

General purpose instances

I hope you find it very helpful and if issue persists, feel free to reach back by replying on here or open an AWS technical support to AWS Premium Support and Contact Us