vCenter Server and ESXi communicate with the storage provider to obtain information that the storage provider collects from underlying physical and software-defined storage, or from available I/O filters. vCenter Server can then display the storage data in the vSphere Web Client.
Information that the storage provider supplies can be divided into the following categories:
Storage data services and capabilities. This type of information is essential for such functionalities as Virtual SAN, Virtual Volumes, and I/O filters. The storage provider collects information about data services that are offered by underlying storage entities or available I/O filters.
You reference these data services when you define storage requirements for virtual machines and virtual disks in a storage policy. Depending on your environment, the storage policy ensures appropriate storage placement for a virtual machine or enables specific data services for virtual disks. For details, see Understanding Virtual Machine Storage Policies.
Storage status. This category includes reporting about status of various storage entities. It also includes alarms and events for notifying about configuration changes.
This type of information can help you troubleshoot storage connectivity and performance problems. It can also help you to correlate array-generated events and alarms to corresponding performance and load changes on the array.
Storage DRS information. For distributed resource scheduling (DRS) on block devices or file systems. Storage providers supply additional information about storage system, so that decisions made by Storage DRS are compatible with resource management decisions internal to the storage systems.