# Launch instances using Capacity Blocks
Launch instances

To use your Capacity Block, you must specify the Capacity Block reservation ID when launching instances. Launching an instance into a Capacity Block reduces the available capacity by the number of instances launched. For example, if your purchased instance capacity is eight instances and you launch four instances, the available capacity is reduced by four.

If you terminate an instance running in the Capacity Block before the reservation ends, you can launch a new instance in its place. When you stop or terminate an instance in a Capacity Block, it takes several minutes to clean up your instance before you can launch another instance to replace it. During this time, your instance will be in a stopping or `shutting-down` state. After this process is complete, your instance state will change to `stopped` or `terminated`. Then, the available capacity in your Capacity Block will update to show another instance available to use.

**Requirements**
+ Your instance can't launch in a subnet in a different Availability Zone from the Availability Zone where your Capacity Block is located.
+ Your instance can't launch using an AMI with a different platform than the platform for your Capacity Block.
+  To use Capacity Blocks in Local Zones, you must be opted in to the Local Zone. 

------
#### [ Console ]

**To launch instances into a Capacity Block**

1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/).

1. In the navigation bar at the top of the screen, select the Region for your Capacity Block reservation.

1. From the Amazon EC2 console dashboard, choose **Launch instance**.

1. Follow the procedure to [launch an instance](ec2-launch-instance-wizard.md).

1. Expand **Advanced details**, and for **Purchasing option**, choose **Capacity Blocks**. Then do one of the following:
   + To launch the instances into a specific Capacity Block, for **Capacity Reservation** choose **Specify Capacity Reservation**, and then select the Capacity Block.
   + (*UltraServers only*) To launch the instances into an UltraServer Capacity Block resource group, for **Capacity Reservation** choose **Specify Capacity Reservation resource group**, and then select the resource group.

1. Choose **Launch instance**.

------
#### [ AWS CLI ]

**To launch instances using into a Capacity Block**  
Use the [run-instances](https://docs.aws.amazon.com/cli/latest/reference/ec2/run-instances.html) command with the `instance-market-options MarketType` option.

The following example launches an instance into a specific Capacity Block.

```
aws ec2 run-instances \
--image-id ami-0abcdef1234567890 \
--count 1 \
--instance-type p5.48xlarge \
--key-name my-key-pair \
--subnet-id subnet-0abcdef1234567890 \
--instance-market-options MarketType='capacity-block' \
--capacity-reservation-specification CapacityReservationTarget={CapacityReservationId=capacity_block_id}
```

The following example launches an instance into an UltraServer Capacity Block resource group.

```
aws ec2 run-instances \
--image-id ami-0abcdef1234567890 \
--count 1 \
--instance-type p6e-gb200.36xlarge \
--key-name my-key-pair \
--subnet-id subnet-0abcdef1234567890 \
--instance-market-options MarketType='capacity-block' \
--capacity-reservation-specification CapacityReservationTarget={CapacityReservationResourceGroupArn=resource_group_arn}
```

------
#### [ PowerShell ]

**To launch instances into a Capacity Block**  
Use the [New-EC2Instance](https://docs.aws.amazon.com/powershell/latest/reference/items/New-EC2Instance.html) cmdlet with the `-InstanceMarketOption` option defined as follows.

```
$marketoption = New-Object Amazon.EC2.Model.InstanceMarketOptionsRequest
$marketoption.MarketType = "capacity-block"
```

The following example launches an instance into a specific Capacity Block.

```
New-EC2Instance `
-ImageId ami-0abcdef1234567890 `
-InstanceType p5.48xlarge `
-KeyName "my-key-pair" `
-SubnetId subnet-0abcdef1234567890 `
-InstanceMarketOptions $marketoption `
-CapacityReservationTarget_CapacityReservationId capacity_block_id
```

The following example launches an instance into an UltraServer Capacity Block resource group.

```
New-EC2Instance `
-ImageId ami-0abcdef1234567890 `
-InstanceType p6e-gb200.36xlarge `
-KeyName "my-key-pair" `
-SubnetId subnet-0abcdef1234567890 `
-InstanceMarketOptions $marketoption `
-CapacityReservationTarget_CapacityReservationResourceGroupArn "resource_group_arn"
```

------

**Related resources**
+ To create a launch template targeting a Capacity Block, see [Store instance launch parameters in Amazon EC2 launch templates](ec2-launch-templates.md).
+ To launch instances into a Capacity Block using EC2 Fleet, see [Tutorial: Configure your EC2 Fleet to launch instances into Capacity Blocks](ec2-fleet-launch-instances-capacity-blocks-walkthrough.md).
+ To set up an EKS managed node group with a Capacity Block, see [Create a managed node group with Capacity Blocks for ML](https://docs.aws.amazon.com/eks/latest/userguide/capacity-blocks-mng.html) in the **Amazon EKS User Guide**.
+ To set up AWS ParallelCluster using a Capacity Block, see [ML on AWS ParallelCluster](https://catalog.workshops.aws/ml-on-aws-parallelcluster/en-US).