I'm trying to figure out the best way to start small instance - 1.7GB RAM, 1 ECU on AWS and be able to resize it up to 7.5GB Large and beyond - and likewise to come down from a 7.5gb large to a Small Instance. Has anyone got anywhere with this? I can fire up a micro 64 bit instance but the next step is a large instance, and if I fire up a micro 32-bit, the next and only step is a 1.7GB (okay 1 or 5 ECU's...) max. I like to be able to resize with a reasonable amount of ease between the various instance sizes. Any advice appreciated! Thanks.
Unfortunately you can't move server images between the 32 and 64-bit instance types. Long story short, the different server types require different kernels which are baked into the server images.
Usually your best option for rapidly moving between instance types is to launch and manage your with a automation tool like puppet or chef. Once you're setup with one of these tools and have all of your persistent data on an EBS volume or S3, any individual server essentially becomes ephemeral. Switching between server types is often as easy as pushing a few buttons.
If you don't want to deal with learning and setting up an automation tool like these, then your probably better off moving to Rackspace Cloud or Linode as they have more robust and dedicated tools for migrating between instance sizes.