See the following table for the disks provided by ECS.

Name Code  Maximum capacity per disk (GiB) Volume limit per instance Maximum capacity of disks allowed per instance (GiB)
Basic cloud disk cloud 2000 17 2000 * 17
Ultra cloud disks cloud_efficiency 32768 17 32768 * 17
SSD cloud disks cloud_ssd 32768 17 32768 * 17
ESSD* essd 32768 17 32768 * 17

* Currently, the ESSD disk cannot be managed by calling the Alibaba Cloud ECS API.

For more information, see Storage parameters and performance test.