Launch instances into Capacity Reservations in a group

You can launch instances into your existing Capacity Reservations by specifying a Capacity Reservation Resource Group ARN. Instances that target a group match with any Capacity Reservation in the group that has matching attributes (instance type, platform, Availability Zone, and tenancy) and available capacity.

When you launch instances using the launch instance wizard or the RunInstances API, you can specify only one purchasing option (one reservation type) per launch. To launch into multiple reservation types in the group at once, use Amazon EC2 Fleet or Auto Scaling groups.

For step-by-step walkthroughs on how to launch instances into multiple Capacity Reservation types using a Capacity Reservation Resource Group, see the following tutorials: via EC2 Fleet and via Amazon EC2 Auto Scaling.

On-Demand Capacity Reservations

To launch instances into On-Demand Capacity Reservations in a group, specify the group ARN using the CapacityReservationTarget parameter with the CapacityReservationResourceGroupArn field.

Amazon EC2 launches instances into any matching On-Demand Capacity Reservation in the group. If no matching capacity is available, the instances launch using On-Demand capacity.

If you don't want instances to launch as On-Demand when no matching capacity is available, set CapacityReservationPreference to capacity-reservations-only. With this setting, instances fail to launch if no matching On-Demand Capacity Reservation in the group has available capacity.

Console

To launch instances into On-Demand Capacity Reservations in a group

1. Follow the procedure to launch an instance, but don't launch the instance until you've completed the following steps.

2. Expand Advanced details.

3. For Purchasing option, leave as None (default).

4. For Capacity Reservation, choose Specify Capacity Reservation Resource Group (default) or Only launch in a Capacity Reservation Resource Group (to prevent On-Demand fallback), then select the group.

5. Choose Launch instance.

AWS CLI

To launch instances into On-Demand Capacity Reservations in a group

Use the run-instances command with the --capacity-reservation-specification parameter.

The following example launches instances into a group. If the group does not have an ODCR with matching attributes and available capacity, the instances launch as On-Demand instances.

aws ec2 run-instances \
    --instance-type c5.xlarge \
    --image-id ami-0abcdef1234567890 \
    --count 3 \
    --capacity-reservation-specification \
        CapacityReservationTarget={CapacityReservationResourceGroupArn=arn:aws:resource-groups:sa-east-1:123456789012:group/MyCRGroup}

The following example launches instances into a group. If the group does not have an ODCR with matching attributes and available capacity, the instances fail to launch.

aws ec2 run-instances \
    --instance-type c5.xlarge \
    --image-id ami-0abcdef1234567890 \
    --count 3 \
    --capacity-reservation-specification \
        CapacityReservationPreference=capacity-reservations-only,CapacityReservationTarget={CapacityReservationResourceGroupArn=arn:aws:resource-groups:sa-east-1:123456789012:group/MyCRGroup}

Targeting a specific placement group

Optionally, if your group contains On-Demand Capacity Reservations in a placement group, you can also specify the placement group ID along with the Capacity Reservation Resource Group ARN to place all launched instances into that placement group.

Interruptible Capacity Reservations

To launch instances into interruptible Capacity Reservations in a group, specify the group ARN and select the interruptible purchasing option. Amazon EC2 places instances into any active interruptible Capacity Reservation in the group with matching attributes and available capacity. If no matching capacity is available, the instances fail to launch.

Console

To launch instances into interruptible Capacity Reservations in a group

1. Follow the procedure to launch an instance, but don't launch the instance until you've completed the following steps.

2. Expand Advanced details.

3. For Purchasing option, choose Interruptible Capacity Reservations.

4. For Capacity Reservation, choose Specify Capacity Reservation Resource Group and select the group.

5. Choose Launch instance.

AWS CLI

To launch instances into interruptible Capacity Reservations in a group

Use the run-instances command with the --instance-market-options and --capacity-reservation-specification parameters.

aws ec2 run-instances \
    --instance-type c5.xlarge \
    --image-id ami-0abcdef1234567890 \
    --count 3 \
    --instance-market-options MarketType=interruptible-capacity-reservation \
    --capacity-reservation-specification \
        CapacityReservationTarget={CapacityReservationResourceGroupArn=arn:aws:resource-groups:sa-east-1:123456789012:group/MyCRGroup}

Capacity Blocks

To launch instances into Capacity Blocks in a group, specify the group ARN and select the Capacity Blocks purchasing option. Amazon EC2 places instances into any active Capacity Block in the group with matching attributes and available capacity. If no matching capacity is available, the instances fail to launch.

Console

To launch instances into Capacity Blocks in a group

1. Follow the procedure to launch an instance, but don't launch the instance until you've completed the following steps.

2. Expand Advanced details.

3. For Purchasing option, choose Capacity Blocks.

4. For Capacity Reservation, choose Specify Capacity Reservation Resource Group and select the group.

5. Choose Launch instance.

AWS CLI

To launch instances into Capacity Blocks in a group

Use the run-instances command with the --instance-market-options and --capacity-reservation-specification parameters.

aws ec2 run-instances \
    --instance-type p5.48xlarge \
    --image-id ami-0abcdef1234567890 \
    --count 1 \
    --instance-market-options MarketType=capacity-block \
    --capacity-reservation-specification \
        CapacityReservationTarget={CapacityReservationResourceGroupArn=arn:aws:resource-groups:sa-east-1:123456789012:group/MyCRGroup}