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/Instance Change results in Instance reachability check failed/

Instance Change results in Instance reachability check failed


I changed an instance from t2.medium to c6i.large running Windows Server 2019 and 1 of the status checks fails and says "Instance reachability check failed." If I change back to t2.medium it boots again. How do I fix this?

asked a month ago35 views
2 Answers

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:

answered a month ago
  • I did try a reboot and I tried shutting down from OS prior to instance change, but I still had the same issue. I followed the steps in the link provided as well. I change to m5.large and it was fine, so I am not sure what is going on here.



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

  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

answered 25 days ago

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