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Elastic Compute Service

Overview

Features

This topic describes the features of DDH.

Physical isolation of resources

DDH is a physical server exclusively for your use. You can exclusively use and independently plan the physical resources your DDH (such as CPUs, memory, volumes, and network interfaces), achieving a higher level of isolation and completely avoiding resource contention with other users.

CPU oversubscription

For scenarios with low CPU load requirements, you can increase the number of available vCPUs by setting the CPU oversubscription ratio of DDH, serving different business loads. This improves the density of instances on the host, and effectively reduces business deployment costs. More information, please refer to Setting CPU oversubscription ratio.

Automatic deployment of instances on DDH

You can set a DDH to "Allow automatic deployment". After this, the DDH will be included in the automatic deployment pool under your account. If you do not specify a DDH when creating an instance, the system will select a proper DDH from the automatic deployment pool to deploy the instance for you. For more information, refer to Setting automatic deployment.

Instance-DDH association

Instance-DDH association means that the instance will be fixedly deployed on a DDH. That is, when an instance with Economical Mode enabled is restarted, it will still be deployed on the associated DDH. This feature helps you maintain your instance deployment plan. For more information, please refer to Associating instance with DDH.

Instance migration

You can migrate instances from one DDH to another DDH, from a shared host to a specified DDH, or from a DDH to a shared host based on your business needs. This enables flexible business migration. More information, please refer to Managing ECS instances.

Feature comparison of instances on hosts

The following table lists the differences between instances on DDHs and regular ECS instances on shared hosts. Other instance features not listed here are same for instances on DDHs and regular ECS instances on shared hosts. For details, please refer to the ECS related document.

Item	Instances on DDH	Instances on shared host
Creation type	Creating instances on DDH	Purchasing an instance by following the wizard Quickly purchasing instances Purchase an ECS instance with the same configuration ...
Billing method	Pay-as-you-go DDH and instance billing	Pay-as-you-go Subscription Spot instance RI ··· ECS billing overview
Billed resources	Volume EIP DDH and instance billing	Compute resources (vCPU and memory) Volume EIP ECS billing overview
Instance type	Instance types supported by DDH	Instance types
Instance deletion	It is supported to manually delete instances. When a subscription-based DDH expires or is unsubscribed and the retention period ends, the instance will be automatically released.	Pay-as-you-go instances support manually deleting instances. Subscription-based instances cannot be deleted before they expire, but you can apply to unsubscribe them. After the unsubscription, the instances will be retained for 24 hours before being released. If a subscription-based instance expires or a pay-as-you-go instance is stopped due to overdue payment and this is not handled in time, the instance will be automatically released.
Changing instance type	Change type of instance on DDH	Changing instance types
Deployment set	Not supported	Deployment set overview
Instance launch template	Not supported	Launch template overview

Last updated: 2026.01.16 19:03:59