Terminology Review

Protocol Endpoint

(PE)

A PE is a volume of zero capacity with a special setting in its Vital Product Data (VPD) page that ESXi detects during a SCSI inquiry. The PE effectively serves as a mount point for vVols. A PE is the only FlashArray volume that must be manually connected to hosts to use vVols. The industry term for a PE is "Administrative Logical Unit".

VASA

vSphere APIs for Storage Awareness (VASA) is the VMware-designed API used to communicate between vSphere and the underlying storage, in the case for Pure, the FlashArray.

SOAP

In the Days before REST API was more widely used, SOAP (Simple Object Access Protocol) was a messaging protocol that was used to exchange structured data (information) via web services (HTTP). SOAP uses an XML structure to exchange the information between source and destination. SOAP is heavily used in the management communication of the vSphere environment, vCenter Services and most important for the purpose of this KB, VASA.

Management Path

or

Control Path

This is the TCP/IP path between the compute management layer (vSphere) and the storage management layer (FlashArray). Requests such as creating, deleting and otherwise manage storage is issued on this path. This is done via HTTPS and TLS 1.2 over port 8084 for the FlashArray VASA Provider.

Data Path

or

Data Plane

The Data Path is the established connection from the ESXi hosts to the Protocol Endpoint on the FlashArray. The Data Path is the flow that SCSI Ops are sent and received, just as any traditional SAN. This connection is established over the storage fabric. Today this means iSCSI or Fibre Channel.

SPBM

Storage Policy Based Management (SPBM) is a framework designed by VMware to provision and/or manage storage. Users can create policies of selected capabilities or tags and assign them to a VM or specific virtual disk. SPBM for internal storage is called vSAN, SPBM for external storage is called vVols. A vendor must support VASA to enable SPBM for their storage.

VASA Provider

Storage Provider

A VASA provider is an instance of the VASA service that a storage vendor offers a customer that is deployed in their environment. For the FlashArray the VASA Providers are built into the FlashArray controllers and will be represented as VASA-CT0 and VASA-CT1. The term Storage Provider is used in vCenter to represent the VASA Providers for a given FlashArray.

Virtual Volume (vVol)

Virtual Volumes (vVols) is the name for this full architecture. A specific vVol is any volume on the array that is in use by the vSphere environment and managed by the VASA provider. A vVol based volume is not fundamentally different than any other volume on the FlashArray. The main distinction is that when it is in use, it is attached as a Sub-LUN via a PE, instead of via a direct LUN.

vVol Datastore

vVol Storage Container

The vVol Datastore is not a LUN, file system or volume. A vVol Datastore is a target provisioning object that represents a FlashArray, a quota for capacity, and is a logical collection of config vVols. While the object created in vCenter is represented as a Datastore, the vVol Datastore is really a Storage Container that represents that given FlashArray.

SPS

This is a vCenter deamon called Storage Policy Service (SPS or vmware-sps). The SMS and SPBM services run as part of the Storage Policy Service.

SMS

This is a vCenter Service called Storage Management Service (SMS).

vvold

This is the service running in ESXi that handles the management requests directly from the ESXi host to the VASA provider as well as communicates with the vCenter SMS service to get the Storage Provider information.