A dedicated host is a cloud host whose physical resources are exclusively reserved for a single tenant. As the sole tenant of the cloud host, you do not need to share the physical resources with other tenants. This allows you to completely avoid resource contention with other tenants. You can obtain the physical attributes of the physical server, including the number of CPUs (sockets), number of physical CPU cores, and memory size. Then, you can create Elastic Compute Service (ECS) instances of the specified instance families based on the physical attributes. This helps you independently plan physical resources, meet security compliance requirements, and reduce deployment costs.
For more information, see What is DDH?
Benefits
A shared host is a cloud host whose physical resources are shared by multiple tenants. When you deploy ECS instances on shared hosts, you cannot select the shared hosts. You can only use the shared hosts assigned by the system. Unlike shared hosts, dedicated hosts provide physical resources for your exclusive use and allow you to plan these physical resources based on your business requirements. For example, you can deploy ECS instances on specified dedicated hosts or view the physical attributes of dedicated hosts, including the number of sockets (CPUs) and the number of physical cores. The following figure shows the differences between dedicated hosts and shared hosts.
ECS instances deployed on dedicated hosts can meet the following typical requirements:
Security compliance: ECS instances are physically isolated and meet the regulatory requirements of sensitive business.
Support for bring your own license (BYOL): If you have purchased licenses for sockets and physical cores, you can import BYOL images to ECS and use the images to create ECS instances without the need to purchase the licenses again. This way, you can reduce cloud migration costs.
Lower deployment costs: The CPU overprovisioned dedicated host type is provided to reduce unit deployment costs by increasing the number of available vCPUs under the same conditions of physical resources.
Self-planning of physical resources: You can deploy ECS instances on specified dedicated hosts or migrate ECS instances between shared and dedicated hosts or between dedicated hosts. You can also associate ECS instances with dedicated hosts to ensure that the instances always reside on the same dedicated hosts. For example, when you reactivate a pay-as-you-go instance that was stopped in economical mode and has its computing resources released, the instance remains on the associated dedicated host.
Billing
For information about billing, see Overview.
After you purchase a dedicated host, you are not charged for the computing resources (vCPUs and memory) or local disks when you create ECS instances on the dedicated host. However, if the instances use other billable resources such as paid images, cloud disks, and public bandwidth, you are charged for these resources. For more information, see Resource billing for ECS instances on a dedicated host.
Usage notes
You can create a dedicated host in the ECS console and then create ECS instances on the dedicated host. Perform the following steps:
Create a dedicated host.
For more information, see Create a dedicated host.
Create ECS instances on the dedicated host.
For more information, see Create ECS instances on a dedicated host.
Manage the dedicated host.
For more information, see Manage Dedicated Host.
For information about how to manage dedicated hosts and ECS instances, see What is DDH?