Block Storage charges you for pre-configured capacity even if the disk is unattached or has minimal write operations. To optimize performance and cost, regularly monitor and identify underused, overused, or unattached cloud disks and adjust their capacity to match actual usage.
Delete cloud disks that are not attached or used
The simplest way to reduce storage cost is to find and delete cloud disks that are not attached to ECS instances. If a cloud disk is not set to be released together with its ECS instance, the disk persists after the instance is stopped or terminated and continues to incur fees. You must manually delete such disks. You can also check whether any read or write operations were performed on a cloud disk in the past few weeks. If a cloud disk in a non-production environment has been unused for several weeks or unattached for one month, we recommend that you delete it promptly.
Adjust cloud disk capacity
For an overused cloud disk, you can scale up the disk online or offline to increase its capacity. For enhanced SSDs (ESSDs), you can upgrade the performance level (PL) online to meet your performance and capacity requirements.
You can downgrade the PL of a pay-as-you-go ESSD online to reduce storage capacity and cost.
You can also re-initialize a cloud disk to restore the disk to the state when it was created.
Delete old snapshots
If you use automatic snapshot policies that take daily or weekly snapshots, a large number of snapshots accumulate over time. Regularly clean up unnecessary snapshots to reduce storage costs. You can set a retention period in automatic snapshot policies to automatically delete expired snapshots. Deleting snapshots does not affect Block Storage.