Modify supported instance types for an existing Amazon EC2 Dedicated Host

You can modify a Dedicated Host to change the instance types that it supports. If it currently supports a single instance type, you can modify it to support multiple instance types within that instance family. Similarly, if it currently supports multiple instance types, you can modify it to support a specific instance type only.

To modify a Dedicated Host to support multiple instance types, you must first stop all running instances on the host. The modification takes approximately 10 minutes to complete. The Dedicated Host transitions to the pending state while the modification is in progress. You can't start stopped instances or launch new instances on the Dedicated Host while it is in the pending state.

To modify a Dedicated Host that supports multiple instance types to support only a single instance type, the host must either have no running instances, or the running instances must be of the instance type that you want the host to support. For example, to modify a host that supports multiple instance types in the m5 instance family to support only m5.large instances, the Dedicated Host must either have no running instances, or it must have only m5.large instances running on it.

If you allocate a host for a virtualized instance type, you can't modify the instance type to a .metal instance type after the host is allocated. For example, if you allocate a host for the m5.large instance type, you can't modify the instance type to m5.metal. Similarly, if you allocate a host for a .metal instance type, you can't modify the instance type to a virtualized instance type after the host is allocated. For example, if you allocate a host for the m5.metal instance type, you can't modify the instance type to m5.large.