Permissions

If you need to assign different permissions to employees in your enterprise to access your DSS resources, Identify and Access Management (IAM) is a good choice for fine-grained permissions management. IAM provides identity authentication, permissions management, and access control, helping you securely access your Huawei Cloud resources.

With IAM, you can use your Huawei Cloud account to create IAM users for your employees, and assign permissions to the users to control their access to specific resources. For example, some software developers in your enterprise need to use DSS resources but should not be allowed to delete them or perform any high-risk operations. In this scenario, you can create IAM users for the software developers and grant them only the permissions required for using DSS resources.

If your Huawei Cloud account does not require individual IAM users for permissions management, skip this section.

IAM can be used free of charge. You pay only for the resources in your account. For more information about IAM, see IAM Service Overview.

DSS Permissions

By default, new IAM users do not have permissions assigned. You need to add a user to one or more groups, and attach permissions policies or roles to these groups. Users inherit permissions from the groups to which they are added and can perform specified operations on cloud services based on the permissions.

DSS is a project-level service deployed and accessed in specific physical regions. To assign DSS permissions to a user group, specify the scope as region-specific projects and select projects for the permissions to take effect. If All projects is selected, the permissions will take effect for the user group in all region-specific projects. When accessing DSS, the users need to switch to a region where they have been authorized to use this service. When accessing DSS, the users need to switch to a region where they have been authorized to use this service.

You can grant users permissions by using roles and policies.

Roles: A type of coarse-grained authorization mechanism that defines permissions related to user responsibilities. This mechanism provides only a limited number of service-level roles for authorization. When using roles to grant permissions, you need to also assign other roles on which the permissions depend to take effect. However, roles are not an ideal choice for fine-grained authorization and secure access control.
Policies: A type of fine-grained authorization mechanism that defines permissions required to perform operations on specific cloud resources under certain conditions. This mechanism allows for more flexible policy-based authorization, meeting requirements for secure access control. For example, you can grant ECS users only the permissions for managing a certain type of ECSs. Most policies define permissions based on APIs. For the API actions supported by DSS, see Permissions Policies and Supported Actions.

Table 1 lists all the system-defined roles and policies supported by DSS.

**Table 1** System-defined roles and policies supported by DSS
Role/Policy Name	Description	Type	Dependencies
DSS FullAccess	Full permissions for DSS. Users granted with this permission can create, expand, and query DSS resources.	System-defined policy	N/A
DSS ReadOnlyAccess	Read-only permission for DSS. Users granted with this permission can query DSS resources only.	System-defined policy	N/A

Table 2 lists the common operations supported by each system-defined policy or role of DSS. Select the policies or roles as required.

**Table 2** Common operations supported by each system-defined policy or role of DSS
Operation	DSS FullAccess	DSS ReadOnlyAccess
Creating storage pools	√	×
Querying storage pools	√	√
Expanding storage pool capacities	√	×
Expanding disk capacity	√	×
Creating disks	√	×
Querying disks	√	√
Detaching disks	√	×
Deleting disks	√	×