Reachability for a new instance fails. Cannot connect to the instance.


I created an instance from an image that I had created from a snapshot. The original image is t4g.large, however, when creating an instance from this image I was able to only create t3.large (the option for t4g.large was greyed out). The instance creation went fine but now I am not able to connect to my instance. Under the Status Check I see "Instance reachability check failed. Check failure at 2023/01/13 15:58 GMT+5:30 (10 minutes)" Availability zone is us-west-2d.

Any inputs on this would be highly appreciated.

asked a year ago304 views
2 Answers

Check this out: Compatibility for changing the instance type.

You should not be able to use an image for Graviton2 CPU to create an x86 CPU instance.

profile pictureAWS
answered a year ago
  • So how do I create an instance from my t4g? As of today, Gravitron2 is disabled for Ubuntu OS, however when I first created this instance, it was okay to do so.

  • I was able to launch a t4g instance with the Ubuntu image. Can you post the output from an 'aws ec2 describe-images --image-ids <AMI-ID>' command of the image you are trying to use?

  • {
        "Images": [
                "Architecture": "x86_64",
                "CreationDate": "2023-01-13T09:36:53.000Z",
                "ImageId": "ami-04c7dbe67ffd1628e",
                "ImageLocation": "479331394205/",
                "ImageType": "machine",
                "Public": false,
                "OwnerId": "479331394205",
                "PlatformDetails": "Linux/UNIX",
                "UsageOperation": "RunInstances",
                "State": "available",
                "BlockDeviceMappings": [
                        "DeviceName": "/dev/sda1",
                        "Ebs": {
                            "DeleteOnTermination": true,
                            "SnapshotId": "snap-08299c3809eb888ba",
                            "VolumeSize": 40,
                            "VolumeType": "gp2",
                            "Encrypted": false
                "Description": "This will be for test purposes once the main domain redirects.",
                "EnaSupport": true,
                "Hypervisor": "xen",
                "Name": "",
                "RootDeviceName": "/dev/sda1",
                "RootDeviceType": "ebs",
                "SriovNetSupport": "simple",
                "Tags": [
                        "Key": "Name",
                        "Value": "devex2"
                "VirtualizationType": "hvm"
  • You can see in the output, "Architecture": "x86_64". That Image was taken from an Intel or AMD instance. It can't be used to create a Graviton2 (t4g.*) instance.

  • It's strange since the Lifecycle Manager creates a backup of the Graviton2 instance, but then it won't let me create an instance of the same type again. Any ideas on how I can clone this instance? Thank you again for helping me out.

    EDIT: I was able to create an image from the live server and launch an instance with that and that worked. However, when I create images from the snapshots created by the Lifecycle Manager, they are not compatible with Graviton2. Don't know why. This also negates the purpose of the backups created with the Lifecycle Manager.


Hi! I am starting to check SG & NACL

answered a year ago

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