Hello,
If a data disk is no longer required, you can soft delete or permanently delete it. A soft deleted data disk is stored in the recycle bin. A soft deleted data disk can be restored from the recycle bin. A permanently deleted data disk cannot be restored.
Restrictions
If a disk has been attached to an instance, the disk cannot be deleted.
If a disk has been configured with the disaster recovery service (CSDR, CSHA, or VHA), the disk cannot be deleted.
If a disk is created using vAPP, the disk cannot be deleted.
If an EVS disk has a snapshot, the EVS disk can be soft deleted only when the snapshot is in the Available or Error state.
When an EVS disk is permanently deleted, all snapshots of the EVS disk are also deleted.
A shared disk to be deleted must have been detached from all instances.
Procedure
Log in to EVS Console as a VDC administrator or VDC operator.
On the Elastic Volume Service page, locate the row that contains the target data disk, click More in the Operation column, and choose Delete.
To delete multiple data disks at a time, tick
before the data disks on the Elastic Volume Service page.
Delete the data disk.

If you want to delete an EVS disk permanently, select By selecting this option, the disk will be permanently deleted instead of being deleted to the recycle bin., and click OK.
When an EVS disk is permanently deleted, all snapshots of the EVS disk are also deleted.
If you want to delete a data disk but require that the deleted data disk can be restored later, click OK to soft delete the data disk.
If deleting a data disk requires approval, contact the administrator for approval. Otherwise, skip this step.
After a data disk is permanently deleted, it is no longer displayed in the EVS disk list.
After a data disk is soft deleted, the status of the data disk changes to Soft deleted.
Follow-up Procedure
A deleted EVS disk is stored in the recycle bin and still occupies storage space.
To restore data on a disk that has been soft deleted, choose . On the Recycle Bin page, select the target EVS disk and click Restore.
To permanently delete an EVS disk that has been soft deleted, choose . On the Recycle Bin page, select the target EVS disk and click Delete Permanently.
For details
https://support.huawei.com/enterprise/my/doc/EDOC1100105755/b1315ae8/deleting-a-data-disk
Thanks