Expanding Disk Capacity

Function

As workloads increase, disk space is likely to become the first bottleneck. When other resources such as CPUs and memory are still ample, increasing storage through the conventional scale-out method (adding nodes) is not only time-consuming but also wastes CPU and memory resources. Elastic disk capacity expansion allows you to expand the disk storage capacity of a cluster without adding nodes to quickly alleviate storage resource bottlenecks. Disk capacity expansion does not suspend services and does not waste CPU or memory resources. If the disk space is still insufficient after capacity expansion, you can continue to expand disk capacity. If the capacity expansion fails, you can submit the task again.

Notes and Constraints

Disk capacity expansion is irreversible. After capacity expansion, capacity reduction is not supported. Plan the disk capacity you need based on service requirements to avoid resource waste.

• Disk capacity expansion is available only for clusters of version 8.1.1.203 or later. During cluster creation, the storage type must be set to SSD.
• Disk capacity can be expanded only if the cluster is in Available, To be restarted, Read-only, Unbalanced, Node fault, or Unavailable state.

• Hot data storage supports only disk capacity expansion and does not support capacity reduction. (Disk capacity expansion cannot be rolled back.)
• You are advised to expand the capacity of hot data storage during off-peak hours to minimize the impact on performance.
• If a cluster is read-only or becomes unavailable when the disk space is used up, a message will be displayed after you click Change Disk Capacity. After you start expansion, the cluster will become available.

Procedure

1. Log in to the DWS console.
2. In the navigation pane on the left, choose Cluster > Cluster List. All clusters are displayed by default.
3. In the Operation column of the target cluster, choose More > Change Specifications > Change disk capacity and click OK.
4. On the Change disk capacity page, set the parameters listed in the following table.

   Table 1 Parameters for disk capacity expansion

   Parameter	Description
   Cluster Name	Cluster for which the disk capacity is to be expanded
   Hot Storage/Hot storage (with cache)	Hot data storage capacity of the current cluster. For Storage-Compute Decoupled clusters, Hot Storage (Including Cache) is displayed. For storage-compute coupled clusters, Hot Data Storage is displayed.
   Added Capacity	Select the appropriate storage space based on the storage step of the corresponding flavor. The step refers to the interval for increasing or decreasing storage space. For details about the step of each flavor, see Data Warehouse Flavors.
   Total Storage/Hot Storage After Scaling (with Cache)	Storage capacity after scaling
   Existing Nodes	Number of nodes in the current cluster
   Total	Total resources of the current cluster after disk capacity expansion
   Billing Mode	Billing mode of the current cluster

5. Confirm the settings, select I agree, and click Resize Cluster Now.
6. Confirm the settings and click Submit.
7. Click Back to Cluster List and check the disk capacity expansion progress.

Hybrid Billing for Disk Capacity Expansion of a Yearly/Monthly Cluster

Only storage-compute decoupled clusters support hybrid billing.

Differences Between Disk Capacity Expansion and Node Addition