Editing the default EC2 launch template - AWS Elastic Disaster Recovery
Amazon EC2 launch template parametersAmazon EC2 template considerations

Editing the default EC2 launch template

To edit the default EC2 launch template, take the following steps:

  1. Select Default launch from the left-hand navigation menu (under Settings).

  2. Click Edit in the Default EC2 launch template section.

  3. Change the settings according to your preferences.

  4. Click Save.

Amazon EC2 launch template parameters

AWS Elastic Disaster Recovery (AWS DRS) Amazon EC2 launch settings are divided into basic and advanced settings.

The basic settings include:

  • Subnet – When you specify a subnet, this field defines where the instance will be launched. When selecting a subnet, only the default network interface will be updated. If you do not include a subnet, the launched instance will use the Region’s default subnet.

  • Security groups – The selected security groups to assign to the instance, applied to the subnet selected for the default network interface. If no security group is selected, there is no default value and no group will be used. Security groups can only be selected if a subnet is included.

  • Instance type – The default instance type to use when launching. If instance type right-sizing is active, the system will disregard this setting. If no instance type is included, a default value will be used. You can either select an instance type, or you can specify instance attributes and let Amazon EC2 identify the instance types with those attributes.

  • EBS volume type – Applies to all volumes for which this type is relevant. If an unmatching type exists, the default type (GP3) will be used instead. Some volume types require setting additional values such as IOPS or throughput.

Instance type attributes:

  • Number of vCPUs: Enter the minimum and maximum number of vCPUs for your compute requirements. To indicate no limits, mark the no minimum or no maximum checkboxes.

  • Amount of memory (MiB): Enter the minimum and maximum amount of memory, in MiB, for your compute requirements. To indicate no limits, mark the no minimum or no maximum checkboxes.

  • Expand Optional instance type attributes and choose Add attribute to express your compute requirements in more detail. For information about each attribute, see InstanceRequirementsRequest in the Amazon EC2 API Reference.

  • Preview matching instance types: You can preview the instance types that match the specified attributes. To exclude instance types, you can select the instance types you want to exclude from the previewed list of instance types, but only if you did not allow list instance types, as you can either exclude or allowlist instance types but not both.

See more about these attributes here: How attribute-based instance type selection works. EC2 will use fleets to launch your instances, and will apply price protection to ensure the fleet does not pick expensive instance types for you. We use the default protection settings, so we will protect against selecting instance types that are 20% more expensive than the lowest cost instance type. To learn more about price protection using fleets, visit: Price protection.

To learn more about using instance type attributes in DRS, visit Flexible Instance Types

Advanced settings include additional parameters that add specific features to the EC2 template. If you choose not to include these parameters in the template, the specific capabilities will not be added.

The advanced settings include:

  • IAM instance profile – Attach a specific profile to the instance that will be launched. Make sure the instance profile has the AWSElasticDisasterRecoveryRecoveryInstancePolicy IAM policy attached in addition to any other policy.

  • Auto assign public IP – Automatically assign a public IP to the launched instance.

  • Termination protection – Protect the launched instance from accidental termination using the EC2 console.

  • Tenancy – Set tenancy information, such as dedicated host needed in conjunction with setting BYOL for Windows servers and Windows Home.

  • Capacity reservation – Apply reservation consideration to the launched instances.

  • Key pair – Associate a key pair with launched instances that are based on EC2 instances.

Note

AWS DRS only supports major EC2 template parameters. If you want to change values that are not supported by this feature, you can still do so by editing the EC2 launch template via the Amazon EC2 console:

  • Create a new EC2 template version with the required changes.

  • Mark it as default.

Important

Every time you modify an EC2 launch template on the Amazon EC2 console, a new version is created. AWS DRS uses the version that is marked as the default. if you prefer to use the EC2 launch template you just modified, make sure to mark it as the default. Changes made through the AWS DRS console are automatically set as the default version.

EC2 launch template tags – In addition to the basic and advanced settings, you can also add up to 50 tags. These will be transferred to EC2 launch template created by AWS Elastic Disaster Recovery (AWS DRS) service.

Learn more about EC2 launch template settings and configuration options in this EC2 article.

Amazon EC2 template considerations

  1. Revert to previous version – The right-sizing mechanism can fix issues such as an incorrect instance type, but other issues may still occur. If you encounter any issues with the launch template, you can quickly address them by choosing the original default launch template that was created by AWS DRS when the agent was installed. Alternatively, you can edit the relevant fields from the AWS DRS console.

  2. IOPS – If needed, set the number of I/O operations per second that the volume can support via the Amazon EC2 console. You can select any number as long as it matches the Amazon EBS guidelines.

    • Provisioned IOPS SSD (io1): 50 IOPS per GiB of storage

    • Provisioned IOPS SSD (io2): 500 IOPS per GiB of storage

    • General Purpose SSD (gp3): 500 IOPS per GiB of storage