Amazon Elastic Compute Cloud
User Guide (API Version 2014-06-15)
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Modifying Your Reserved Instances

When your computing needs change, you can modify your Reserved Instances and continue to benefit from your capacity reservation. You can move your Reserved Instances between Availability Zones within the same region, and you can change the network platform between EC2-Classic and EC2-VPC. Availability Zone and network platform modifications are supported for all product platform types.

In addition, starting with Amazon EC2 API version 2013-10-01, you can change the instance type of your reservation to a larger or smaller instance type in the same family (e.g., the M1 instance family), if capacity is available, and if you are modifying a Reserved Instance associated with the Linux/UNIX product platform. Instance type modifications are not supported for other platform types.

Modification does not change the remaining term of your Reserved Instances. Their end dates remain the same. There is no fee for modifying your Reserved Instances, and you do not receive any new bills or invoices.

Instances covered by Reserved Instances continue to run even if you modify your reservation. However, after modification, the pricing benefit of the Reserved Instances starts applying to instances that match the new parameters of your Reserved Instances. You are charged at the On-Demand rate for the EC2 instances no longer receiving the benefits of the modified Reserved Instances, unless your account has other applicable reservations, in which case you will be charged at the rate of these other Reserved Instances.

Modification does not affect how you use, purchase, or sell Reserved Instances. When you purchase Reserved Instances, you still need to specify the product platform, instance type, network platform, tenancy, term length, offering type, and Availability Zone.

Note

To purchase and modify Reserved Instances, ensure that your account has the appropriate permissions, such as the ability to describe Availability Zones. For information, see the IAM Best Practices and the Permissions and Policies sections in the Using IAM guide.

You can view the status of your request in the AWS Management Console, or when you call the DescribeReservedInstancesModifications API action or ec2-describe-reserved-instances-modifications CLI command.

This section discusses the modification process:

Understanding the Modification Process

You can modify your Reserved Instances in one or more of the following ways:

  • Move them between Availability Zones within the same region.

    If you modify the Availability Zone of your Reserved Instances, the capacity reservation and pricing benefit stop applying to instance usage in the original zone, and start applying to usage in the new Availability Zone.

  • Change the network platform of the Reserved Instances between EC2-VPC and EC2-Classic.

    If you modify the network platform of your Reserved Instances, the capacity reservation stops applying to instance usage with the original network platform, and starts applying to usage with the new network platform. However, the pricing benefit continues to apply to both EC2-Classic and EC2-VPC instance usage matching the remaining Reserved Instances parameters.

  • Upgrade or downgrade the instance type of your Reserved Instances within the same instance family (e.g., the M1 instance family).

    If you modify the instance type of your Reserved Instances, you must ensure that the instance family of your reservation has a larger or smaller instance type available and that you have enough applicable Reserved Instances to make the change.

You can modify your whole reservation or a subset of your reservation. When you modify a subset of your reservation, Amazon EC2 splits your original Reserved Instances into two or more new Reserved Instances. For example, if you have Reserved Instances for 10 instances in us-east-1a, and decide to move 5 instances to us-east-1b, the modification request results in two new Reserved Instances—one for 5 instances in us-east-1a (the original zone), and the other for 5 instances in us-east-1b.

Amazon EC2 fulfills your modification request as soon as possible, depending on available capacity. Until your modification request completes, the capacity reservation and pricing benefit associated with your Reserved Instances continue to be based on the original parameters of your reservation.

Note

You cannot cancel or change a pending modification request after you submit it. While your modification is being processed, the status of the Reserved Instances that you're modifying is active (pending modification). After the modification has completed successfully, you can submit another modification request to roll back any changes you made.

If your Reserved Instances modification request succeeds:

  • The modified reservation becomes effective immediately and the pricing benefit of the Reserved Instances is applied to the new instances beginning at the hour of the modification request. For example, if you successfully modify your Reserved Instances at 9:15PM, the pricing benefit transfers to your new instance at 9:00PM. (You can get the effective date of the modified Reserved Instances by using the DescribeReservedInstances API action or the ec2-describe-reserved-instances CLI command.)

  • The end date of the modified Reserved Instances is the same as the original end date of the reservation. If you successfully modify a three-year reservation that had 16 months left in its term, the resulting modified reservation is a 16-month Reserved Instance with the same end date as the original Reserved Instances.

    For example, in the following table, Modification #1 shows RI af9f760... was modified successfully and retired on 2013-08-30 16:00 UTC-7 and a new RI 46a408c... was created as a result of the modification on the same date-time that RI af9f760... was retired. Modification #2 shows RI 46a408c... was modified successfully and retired on 2013-09-03 14:00 UTC-7 and a new RI b847fa9... was created as a result of the modification on the same date-time that RI 46a408c... was retired.

  • The original reservation is retired. Its end date is the start date of the new reservation, and the end date of the new reservation is the same as the end date of the original Reserved Instance when it was active.

  • The modified Reserved Instances shows $0 fixed price and not the fixed price of the original Reserved Instances.

    Note

    The fixed price of the modified reservation does not affect the discount tier calculations applied to your account, which are based on the fixed price of the original reservation.

If your modification request fails:

  • Your Reserved Instances maintain the original properties that they had prior to your request.

  • Your Reserved Instances are available for another modification request.

You can determine the status of your request by looking at the state of the Reserved Instances that you are modifying. For information, see Determining the Status of Your Modification.

Determining the Status of Your Modification

The state of your modification request is displayed in the State field in the AWS Management Console. You can also use the DescribeReservedInstancesModifications API action to get detailed information about your modification request: The state returned shows your request as in-progress, fulfilled, or failed.

You can only modify your Reserved Instances if they are active. You are not able to modify Reserved Instances that are in any other state. You also cannot modify your Reserved Instances if they are listed in the Reserved Instance Marketplace. For more information, see Requirements for Modification. If your Reserved Instances are not in the active state or cannot be modified, the Modify Reserved Instances button in the AWS Management Console is not enabled. If you use the API to modify Reserved Instances that are not active, you will get an error.

In cases when you select Reserved Instances whose Availability Zone and network platform can be modified, but whose instance types cannot be changed, the Modify Reserved Instances button is enabled and you can proceed to the Modify Reserved Instances page. However, you do not have the option to modify the instance type. For more information, see Changing the Instance Type of Your Reservations.

Modification States

The modification request is being processed. While the modification request is being processed, the status of the Reserved Instances being modified show as active (pending modification). The Reserved Instances are in this state only for a short period. The state reverts to active or becomes retired, depending on the success of the modification. (If you use the DescribeReservedInstancesModifications API action, the status of your modification request should show processing.)

The modification succeeded. If the modification is successful, the Reserved Instances being modified are retired, and new Reserved Instances are created with the modification configuration that you requested. The status of these new Reserved Instances is active. (If you use the DescribeReservedInstancesModifications API action, the status of your modification request should show fulfilled.)

Note

For the brief period that the new Reserved Instances are being activated, the original Reserved Instances show as retired (pending modification).

The modification failed. If the modification did not complete, the Reserved Instances being modified return to the active state. (If you use the DescribeReservedInstancesModifications API action, the status of your modification request should show failed.) For information about why some Reserved Instances cannot be modified, see Requirements for Modification.

Requirements for Modification

Amazon EC2 processes your modification request if the following conditions are met:

  • We have sufficient Reserved Instances capacity for your target configuration.

  • The Reserved Instances you are modifying are active.

  • The Reserved Instances are not pending another modification request.

    You may modify your Reserved Instances as frequently as you like. However, you cannot submit a modification request for Reserved Instances that are still pending a previous modification request; that is, if the previous modification request is in the active (pending modification) state. For information about modification states, see Determining the Status of Your Modification.

  • The Reserved Instances are not listed in the Reserved Instance Marketplace.

    To modify Reserved Instances that are listed in the Reserved Instance Marketplace, cancel the listing, modify the Reserved Instances, and then list them again.

    In addition, you cannot modify a Reserved Instance Marketplace offering before or at the same time that you purchase it. However, you can submit a modification request after you purchase a Marketplace offering. For more information, see Reserved Instance Marketplace.

  • Only the following attributes are being modified: Availability Zone in the same Region, instance type in the same instance family (e.g., the M1 instance family), and network platform.

  • When combining Reserved Instances, the end dates of the Reserved Instances must have the same hour digits in 24-hour format, but they do not need to have the same minutes or seconds. This means you can combine Reserved Instances if they end on the same day at 13:01 and 13:59, but not if they end at 12:59 and 13:01.

  • When modifying the instance type attribute

    • The Reserved Instances you are modifying must be for the Amazon Linux/UNIX product platform (currently the only product platform for which instance type modifications are allowed).

    • The new instance type of the Reserved Instances must be in the same instance family (e.g., the M1 instance family) as the original reservation.

    • If you are upgrading the instance type of your Reserved Instances, the normalized instance count for the target Reserved Instance configuration must equal the normalized instance count of the original reservation.

    If you select multiple Reserved Instances for modification and one or more of these Reserved Instances are for a product platform that does not allow instance type modification, the Modify Reserved Instances page will not show the option of changing the instance type for any of the selected Reserved Instances. For information about modifying instance types, see Changing the Instance Type of Your Reservations.

  • The attributes for the target Reserved Instance configuration must result in a unique combination of Availability Zone, instance type, and network platform.

For information about how to modify Reserved Instances, see Submitting Modification Requests.