All of this information is taken from the "EC2 User Guide for Linux"
Migrate an instance to another Availability Zone
1. Create an AMI from the instance
- The procedure depends on the operating system and the type of root device volume for the instance.
For more information, see the documentation that corresponds to your operating system and root device volume:
- Creating an Amazon EBS-Backed Linux AMI (p. 88)
- Creating an Instance Store-Backed Linux AMI (p. 91)
- Creating an Amazon EBS-Backed Windows AMI
- Creating an Instance Store-Backed Windows AMI
- If you need to preserve the private IP address of the instance, you must delete the subnet in the current Availability Zone and then create a subnet in the new Availability Zone with the same IP address range as the original subnet. Note that you must terminate all instances in a subnet before you can delete it. Therefore, you should move all instances in the current subnet to the new subnet.
- Launch an instance from the AMI that you just created, specifying the new Availability Zone or subnet. You can use the same instance type as the original instance, or select a new instance type. For more information, see Launching Instances in an Availability Zone (p. 13).
4. Elastic IP
- If the original instance has an associated Elastic IP address, associate it with the new instance. For more information, see Disassociating an Elastic IP Address and Reassociating it with a Different Instance (p. 565).
5. Reserved Instance
- If the original instance is a Reserved Instance, change the Availability Zone for your reservation. (If you also changed the instance type, you can also change the instance type for your reservation.) For more information, see Submitting Modification Requests (p. 216).
- Terminate the original instance. For more information, see Terminating an Instance (p. 310).