A CDH instance is a dedicated physical server equipped with a virtualized environment, which is completely isolated from the servers of other tenants with all its resources exclusive for your use. After purchasing a CDH instance, you can use it by assigning dedicated CVM instances on it, schedule its physical machine resources, and customize dedicated CVM configurations. A common CVM is a physical server whose resources are shared by multiple tenants.
No. CDH instances are physical machines and their hardware configurations cannot be modified after purchase. Please evaluate your requirements carefully before purchasing CDH instances.