This topic provides answers to some commonly asked questions about Dedicated Host (DDH).

What is DDH?

Alibaba Cloud DDH is a single-tenant hosting service. The physical resources of a dedicated host are dedicated for the use of only one tenant. Dedicated hosts of different tenants are isolated at the physical server level. You can create Elastic Compute Service (ECS) instances on a dedicated host. For more information, see What is Dedicated Host (DDH)?

What are the benefits of DDH?

You can bind an existing software license, such as Microsoft Windows Server and Microsoft Windows SQL Server, to an ECS instance that is created on a dedicated host. This reduces the cost of migrating your workloads to the cloud. Dedicated hosts provide greater flexibility, visibility, and control over your application deployment. Dedicated hosts ensure that your applications meet higher compliance and regulatory requirements. For more information, see Benefits.

When can I use DDH?

You can use DDH in some specific scenarios. For more information, see Scenarios.

Is DDH a bare metal product?

No, DDH is not a bare metal product. The ECS instances that are deployed on a dedicated host are the same as the ECS instances that are deployed on a shared host.

What is the difference between a dedicated host and an ECS Bare Metal Instance?

A dedicated host is a cloud server created based on virtualization technology. ECS Bare Metal Instance is a computing service that combines the elasticity of virtual machines and the performance and features of physical machines. ECS Bare Metal Instances are developed based on state-of-the-art virtualization 2.0 technology developed by Alibaba Cloud. For more information about ECS Bare Metal Instance, see ECS Bare Metal Instances.

How can I create and release a dedicated host?

You can use the ECS console to create a dedicated host. For more information, see Create a dedicated host.

After the subscription for a dedicated host expires, the host is automatically released if you do not renew it within 15 days. For more information, see Subscription.

How can I check the total number of resources and the number of available resources on a dedicated host?

You can check the total number of resources and the number of available resources of the dedicated host as follows:

Can I migrate ECS instances on a shared host to a dedicated host?

Yes, you can migrate ECS instances from a shared host to a dedicated host if both hosts belong to the same account. You can log on to the ECS console to migrate the ECS instances, and then restart these instances. You can restart the ECS instances to deploy them on the specified dedicated host. You cannot migrate subscription ECS instances or preemptible instances. For more information, see Migrate ECS instances from a shared host to a dedicated host.

How can I use bring your own licenses (BYOL) on a dedicated host?

To use BYOL on a dedicated host, follow these steps:
  1. Check the terms and conditions of your BYOL to confirm that you can use the license on a dedicated host. We recommend that you consult a licensing advisor. After you confirm that you can use the license on a dedicated host, proceed to step 2.
  2. Use the ECS console or call the ImportImage operation to import custom images. You can also download the software after you establish a remote connection to the ECS instance. For more information, see Connect to an ECS instance.
  3. Start ECS instances that use these images on a dedicated host. When you run these instances, you may need to authorize the instances or images by using Key Management Service (KMS) before you can activate the instance or images. For more information about KMS, see What is KMS?
  4. When you use BYOL on a dedicated host, you may need to submit an audit table to your license provider. You can view the physical parameters (such as the number of sockets, number of physical CPU cores, and number of vCPUs) of the dedicated host in the report. You can view the report in the ECS console.

Does a dedicated host have a unique ID?

Yes, each dedicated host has a machine code (similar to the asset ID of a physical server, but not the host ID). This machine code uniquely identifies the dedicated host. When a dedicated host is assigned to your account, each machine code corresponds to a single physical server, to ensure easy filing of your assets.

Will Alibaba Cloud use the same machine code on different dedicated hosts?

No, Alibaba Cloud will not use the same machine code on different dedicated hosts. Each machine code corresponds to only one physical server. If you are assigned a new physical server due to warranty expiration or migration, a new machine code is assigned to your dedicated host.

Will the instances on a dedicated host be automatically migrated to a healthy dedicated host in event of a failure?

Alibaba Cloud supports automatic failover upon DDH failure. If you enable the feature, the instances are automatically migrated to a healthy dedicated host when the current host fails. For more information, see Modify the automatic instance migration configuration for a DDH.

How do I select the disk and public network bandwidth when I purchase a dedicated host?

You do not need to select disks or public network bandwidth when you create a dedicated host. You need to select disks and public network bandwidth when you create an ECS instance on the dedicated host. For more information, see Create an ECS instance on a dedicated host.