DDHs have the following limits.

Note If you are using an ECS instance on a DDH, besides the following limits, you must also consider the limits to ECS. For more information, see limit of Elastic Compute Service (ECS).
Item Limit Supply for higher configuration or unlock configuration rights
Permission to create a DDH

Complete real-name registration to create a DDH in the mainland China regions.

Not supported.
Supported network types Virtual Private Cloud (VPC). For more information about VPC, see what is VPC. Not supported.
Billing methods links between a DDH and its ECS instances

Subscription DDH: For both Pay-As-You-Go and Subscription ECS instances.

Not supported.

Configurations of Subscription ECS instances on a Subscription DDH

The expiration time of the ECS instance cannot be later than that of the DDH. Not supported.

Auto-renewal Subscription ECS instances on a Subscription DDH

The expiration of the ECS instance after auto-renewal cannot be later than that of DDH. If the time for auto-renewal is against the rule, auto-renewal fails. Not supported.
Conversion of billing methods of ECS instances on a DDH

Available for the Pay-As-You-Go ECS instances on a Subscription DDH. After conversion, the expiration time of an ECS instance cannot be later than that of a DDH.

Not supported.
Conversion of billing methods of a DDH Not supported. Not supported.
ECS instance migration between shared cloud hosting and DDH

Only Pay-As-You-Go ECS instances can be migrated. Subscription ECS instances and Preemptible instances cannot be migrated.

Not supported.
ECS instance migration between DDHs Instances can be migrated only between DDHs of the same dedicated host type under one account. ECS instances on a DDH with local SSD disks cannot be migrated. Not supported.