AWS, Can't change ec2 instance type

Question

My instance is t1.micro on Ireland, eu-west-a1, in a VPC, connected to Elastic IP and a Load Balancer and under Termination Protection. Root device type: EBS, Root device: /dev/sda1

I started with t1.micro but now I want it m3.medium because we are going in production. The problem is that I stopped my instance, Actions -> Change instance type : and the options that are available are only: t1.micro, m1.small, m1.medium, c1.medium.

Meanwhile on other instances I see that can change the instance type to any options.

What makes this instances different from the others, and how can I solve it

Answer 1

You have created the original Amazon EC2 instance with a 32-bit image - these are only available for the few instance types you mentioned and can not be upgraded to 64-bit instance types, I'm afraid you need to reinstall on a 64-bit instance type and migrate your data across.

• See e.g. RakeshS' answer to How can I upgrade my 32 bit Amazon EC2 EBS backed instance into 64 bit one? for high level instructions how to manually migrate you data to a fresh 64-bit instance.

Please note that AWS has introduced 64-bit Ubiquity in spring 2012, i.e. every instance type can be used with 64-bit images, which (as you just painfully discovered) will make it easier for you to scale vertically (to larger and smaller instances) without having to maintain parallel (32 and 64-bit) AMIs indeed (see EC2 Updates: New Medium Instance, 64-bit Ubiquity, SSH Client for details).

I strongly agree with Eric Hammond's advise to only Use the Same Architecture (64-bit) on All EC2 Instance Types going forward:

Though t1.micro, m1.small, and c1.medium will continue to also support 32-bit AMIs, it is my opinion that there is virtually no reason to use 32-bit instances on EC2 any more.

This is fantastic news!

Sticking with 64-bit instances everywhere all the time gives you the most flexibility to switch the instance type of your running instances, reduces the choices and work necessary when building your own AMIs, and just makes life simpler.