If you haven't noticed, AWS recently announced a feature to change the type of instance on EBS backed instances. This feature is particularly useful if you want to add more computing power to an instance to perform certain task and then can scale it down once the task is done (it is all about using $s efficiently). However some points to be noted:
- This can be done only on EBS backed instances.
- Instance need to be stopped before changing the type. Do remember to save the data on ephemeral storage mount before shutting down.
- New instance type must be compatible with the instance AMI, so you can’t change from small instance to large instance (32 bit to 64 bit or vice versa).
Users perform this action either via the console or via API tools.
ec2-modify-instance-attribute instance_id --instance-type
Can find more information about changing instance attributes here.