Restrictions for Amazon EC2 launch templates

The following restrictions apply to launch templates and launch template versions:

• Quotas – To view the quotas for your launch templates and launch template versions, open the Service Quotas console or use the list-service-quotas AWS CLI command. Each AWS account can have up to a maximum of 5,000 launch templates per Region and up to 10,000 versions per launch template. Your accounts might have different quotas based on their age and usage history.

• Parameters are optional – Launch template parameters are optional. However, you must ensure that your instance launch request includes all required parameters. For example, if your launch template does not include an AMI ID, you must specify an AMI ID when launching an instance with this launch template.

• Parameters not validated – Launch template parameters are not fully validated when you create the launch template. If you specify incorrect values or use unsupported parameter combinations, instances will fail to launch using this launch template. To avoid issues, make sure to specify correct values and use supported parameter combinations. For example, to launch an instance in a placement group, you must specify a supported instance type.

• Tags – You can tag a launch template, but you can't tag a launch template version.

• Immutable – Launch templates are immutable. To modify a launch template, you must create a new version of the launch template.

• Version numbers – Launch template versions are numbered in the order in which they are created. When you create a launch template version, you can't specify the version number yourself.