If you want to use the subscription billing method for the storage of your cluster, you must purchase a specific amount of storage capacity when you purchase the cluster.
Scenarios
The total amount of data of the clusters in specific regions under your Alibaba Cloud account is smaller than 10 TB, and the amount of data generated by your business seldom fluctuates.
Limitations
The amount of storage capacity that you purchase applies only to a single cluster. This may cause resource waste, because the cluster may consume less storage capacity than the purchased amount.
The purchased storage capacity can only be scaled up. Scale-down is not allowed. For more information, see Manually scale up the storage capacity of a cluster.
After the purchased storage capacity is exhausted, your cluster still can be used normally. Data that exceeds the purchased storage capacity is billed on a pay-as-you-go basis. If you purchase a storage plan, the storage plan is first deducted for the data that exceeds the purchased storage capacity. After the storage plan is exhausted, the pay-as-you-go billing method is used. For example, you purchase 100 GB of storage space that uses the subscription billing method and a storage plan of 50 GB, but have 200 GB of data. For the 100 GB of data that exceeds the purchased storage capacity, 50 GB is deducted from the storage plan. The remaining 50 GB is billed on a pay-as-you-go basis.
Use the subscription billing method
For more information about how to use the subscription billing method for your clusters, see Purchase a subscription cluster.