Posted On: Nov 15, 2021

You can now share Amazon EC2 On-Demand Capacity Reservations with another Amazon Web Services account or within your Amazon Organization. When a Capacity Reservation is shared, EC2 instances launched by one Amazon Web Services account can utilize EC2 capacity reserved by another account. This feature is enabled by Amazon Resource Access Manager (RAM), a service that allows you to easily and securely share Amazon Web Services resources.

Launched in Oct 2018, EC2 On-Demand Capacity Reservations let you reserve EC2 capacity in a specific Availability Zone for any duration. Once you create a Capacity Reservation, the EC2 capacity is held for you regardless of whether you run the instances or not. Until now, Capacity Reservations were confined to an Amazon Web Services account. By sharing Capacity Reservations, organizations with EC2 usage spread across multiple Amazon Web Services accounts can plan for capacity needs at an aggregate level. Workloads with fluctuating or complementary compute needs running in different accounts can tap into centrally reserved EC2 capacity. The capacity reservation will stay in the same Availability Zone it was created in, but now multiple Amazon Web Services accounts can access it. As a result, organizations can optimize costs by increasing utilization of reserved capacity. This feature is available at no additional cost.

You can share EC2 Capacity Reservations in three easy steps: create a Resource Share through Amazon Resource Access Manager, add resources (Capacity Reservations) to the Resource Share, and specify the target accounts you wish to share the resources with. You can do this through the Amazon Web Services Management Console, or Amazon SDK/CLI. As before, Regional RI discounts automatically apply to any matching Capacity Reservations. This gives you the flexibility to selectively add capacity reservations and still get the Regional RI discounts for that usage.

To learn more about sharing of Capacity Reservations, visit Capacity Reservation FAQs, or Linux or Windows user guides.