How to specify root volume size of core-os ec2 instance using boto3?

Question

I cannot figure out from documentation and source code how to define size of the root device.

You can specify N additional block devices using BlockDeviceMappings sectio

Answer 1

Same as Steve Jeffereies has mentioned, naming the DeviceName is the key. I was able to use /dev/sda1 which you would usually see on AWS console. The following is a working example using magnetic,

BlockDeviceMappings=[
    {
        'DeviceName': '/dev/sda1',
        'Ebs': {
            'VolumeSize': 30,
            'VolumeType': 'standard'
        }
    }
]