Migrate Amazon EC2 instance from On Demand to Reserved
I’ve decided to change the billing option on my EC2 instance from ‘On Demand’ to ‘Reserved’ thinking that it would be straight forward. No really.
Nevertheless, it’s not that complicated once you understand how Amazon bills you and how the instance model works. And below I’m showing how to do so.
Get sure you’re buying a Reserved Instance with the same settings as your running one. By that I mean, Instance Type (e.g.: m1.small) and Availability Zone (e.g.: us-east-1b). As Amazon says:
[…] the conversion of an on-demand instance to a reserved instance is purely a billing issue. Simply buy a reserved instance, and the instances will be billed as reserved instance. No changes need to be made to your AutoScaling group.
Please note that reserved instances currently need to be purchased for a specific AZ. In order to get the benefit of reserved instance pricing, your AutoScaling group should be configured to launch instances in those AZs.
For example, if you only buy a reserved instance in us-east-1a, you should setup your AutoScaling group to launch instances in us-east-1a. If your AutoScaling group is configured to launch instances in us-east-1a and us-east-1b, and AutoScaling launches an instance in us-east-1b, it will be
billed as an on-demand instance unless you also buy a reserved instance in us-east-1b. (source)
Do you need to move your instance to another Availability Zone? Check how here.
Once you have the needed information about your instance go to your AWS Management Console and:
1) Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
2) Click Reserved Instances on the left in the Navigation pane.
3) In the Reserved Instances page, click Purchase Reserved Instances.
4) In the Purchase Reserved Instances page, specify the details of the Reserved Instances you want to purchase (use familiar filters like Platform, Instance Type, Availability Zone, Term, and Tenancy), and click Search.
5) Select the Reserved Instances that you want, enter the quantity that you want to purchase, and click Add to Cart. You can continue to select more Reserved Instances and add them to your cart.
The Seller column indicates whether the seller is a 3rd Party seller or AWS. Notice that the Term column gives you non-standard terms if the seller is a third-party seller. At the bottom of the page, the Purchase Reserved Instances wizard keeps a running tally of the total in your cart.
Chose the one which best fits your current instance and add it to your cart. Afterwards is just standard checkout.
The Bill, please
As soon as the reservation cost clears your credit card you will see the discounted hourly rate take effect for your already-running instances. Now on you’re not going to be charged on-demand any more.
After moving into a reserved instance I’ve dropped how much I pay from ~$400.00 per year to ~$100.00. Good deal, doesn’t it? 😉