6.5.1

Table Of Contents
As any block-based LUNs, the protocol endpoints are discovered using standard LUN discovery
commands. The ESXi host periodically rescans for new devices and asynchronously discovers block
based protocol endpoints. The protocol endpoint can be accessible by multiple paths. Traffic on these
paths follows wellknown path selection policies, as is typical for LUNs.
On SCSI-based disk arrays at VM creation time, ESXi makes a virtual volume and formats it as VMFS.
This small virtual volume stores all VM metadata files and is called the configVVol. The configVVol
functions as a VM storage locator for vSphere.
Virtual volumes on disk arrays support the same set of SCSI commands as VMFS and use ATS as a
locking mechanism.
Virtual Volumes and NFS Transports
With NAS storage, a protocol endpoint is an NFS share that the ESXi host mounts using IP address or
DNS name and a share name. Virtual Volumes supports NFS version 3 and 4.1 to access NAS storage.
Both IPv4 and IPv6 formats are supported.
No matter which version you use, a storage array can provide multiple protocol endpoints for availability
purposes.
In addition, NFS version 4.1 introduces trunking mechanisms that enable load balancing and
multipathing.
Virtual volumes on NAS devices support the same NFS Remote Procedure Calls (RPCs) that ESXi hosts
use when connecting to NFS mount points.
On NAS devices, a configVVol is a directory subtree that corresponds to a configVVolID. The config
VVol must support directories and other operations that are necessary for NFS.
Virtual Volumes Architecture
An architectural diagram provides an overview of how all components of the Virtual Volumes functionality
interact with each other.
vSphere Storage
VMware, Inc. 273