I want to purchase an EC2 Reserved Instance (RI) for the pricing benefit, but I'm not sure that I will use a particular instance type all the time. Will Convertible Reserved Instances (RIs) work for me instead?
Standard RIs can only be modified. You can modify a Standard RI to change the following attributes:
- Availability Zone or scope
- Network platform (EC2-Classic or VPC)
- Instance size
Convertible RIs can be exchanged as well as modified. You can exchange the RI for comparable RIs depending on their value, which gives you more flexibility to change the instances that your RIs will apply to later.
Exchanging Convertible RIs is free, but you might need to pay a true-up cost if the value is lower than the value of the RIs you're exchanging for.