Find and purchase Capacity Blocks - Amazon Elastic Compute Cloud

Find and purchase Capacity Blocks

To reserve a Capacity Block, you first need to find a block of time when capacity is available that matches your needs. To find a Capacity Block that is available to reserve, you specify the following.

  • The number of instances that you need

  • The duration of time you that you need the instances

  • The date range that you need your reservation

To search for an available Capacity Block offering, you specify a reservation duration and instance count. You must specify reservation durations in 1-day increments up to 14 days, and in 7-day increments up to 182 days. Each Capacity Block can have up to 64 instances, and you can have up to 256 instances across Capacity Blocks.

When you request a Capacity Block that matches your specifications, we provide the details of up to 3 available blocks. All Capacity Blocks end at 11:30AM UTC, so the blocks starting on the same day will have durations that are the closest match to your desired duration. One block will have a duration that is slightly less than your desired duration, while the other will have a duration slightly greater than your desired duration.

The offering details include the start time of the reservation, the Availability Zone for the reservation, and the price of the reservation. For more information, see Capacity Blocks pricing and billing.

You can purchase the Capacity Block offering you are shown, or you can modify your search criteria to see the other options that are available. There is no predefined expiration time for the offering, but offerings are only available on a first-come, first-served basis.

When you purchase a Capacity Block offering, you get an immediate response confirming that your Capacity Block was reserved. After confirmation, you will see a new Capacity Reservation in your account with a reservation type of capacity-block and a start-date set to the start time of the offering that you purchased. Your Capacity Block reservation is created with a state of payment-pending. After the upfront payment is successfully processed, the reservation state changes to scheduled. For more information, see Billing.

You can use one of the following methods to find and purchase a Capacity Block.

Console
To find and purchase a Capacity Block using the console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. In the navigation bar at the top of the screen, select an AWS Region. This choice is important because Capacity Block sizes of 64 instances are not supported for all instance types in all Regions.

  3. In the navigation pane, choose Capacity Reservations, Purchase Capacity Blocks.

  4. Under Capacity attributes, you can define your Capacity Block search parameters. By default, the platform is Linux. If you want to select a different operating system, use the AWS CLI. For more information, see Supported platforms.

  5. Under Total capacity, select the number of instances you want to reserve.

  6. Under Duration, enter the number of days or weeks you need the reservation for.

  7. Under Date range to search for Capacity Blocks, enter the earliest date that you want your reservation to start.

  8. Choose Find Capacity Blocks.

  9. If a Capacity Block is available that meets your specifications, you see an offering under Recommended Capacity Blocks. If there are multiple offerings that meet your specifications, the earliest available Capacity Block offering is shown. To view other Capacity Block offerings, adjust your search inputs and choose Find Capacity Blocks again.

  10. When you find a Capacity Block offering that you want to purchase, choose Next.

  11. (Optional) On the Add tags page, choose Add new tag.

  12. The Review and purchase page lists the start and end date, duration, total number of instances, and price.

    Note

    Capacity Blocks can't be canceled after you reserve them.

  13. In the popup window Purchase a Capacity Block, type confirm, then choose Purchase.

AWS CLI
To find a Capacity Block using the AWS CLI

Use the describe-capacity-block-offerings command.

The following example searches for a Capacity Block that has 16 p5.48xlarge instances with a date range starting 2023-08-14 and ending 2023-10-22 with a duration of 48 hours.

aws ec2 describe-capacity-block-offerings --instance-type p5.48xlarge \
  --instance-count 16 --start-date-range 2023-08-14T00:00:00Z \
  --end-date-range 2023-10-22-T00:00:00Z --capacity-duration 48
To purchase a Capacity Block using the AWS CLI

Use the purchase-capacity-block command and specify the offering ID of the Capacity Block that you want to purchase and the instance platform.

aws ec2 purchase-capacity-block \
  --capacity-block-offering-id cbr-0123456789abcdefg \
  --instance-platform Linux/UNIX