Which storage protocol is used by Nutanix Distributed Storage Fabric (DSF) to provide access to an ESXi hypervisor?

The Nutanix Distributed Storage Fabric (DSF) presents storage to a VMware ESXi hypervisor using the Network File System (NFS) protocol. Each Controller VM (CVM) in the Nutanix cluster runs an NFS server that exports storage containers as NFS shares. The ESXi hypervisor on each node mounts this share, which is presented over a virtual internal network switch, as a datastore. This design leverages data locality, allowing a VM's I/O requests to be handled by the local CVM, which optimizes performance by minimizing network latency.

A. LVM: Logical Volume Manager (LVM) is a disk management technology used within a Linux operating system; it is not a network storage protocol for hypervisor access.

B. iSCSI: Nutanix uses the iSCSI protocol for presenting storage to Microsoft Hyper-V clusters and for its external block storage service, Nutanix Volumes, not for ESXi datastores.

C. SMB: The Server Message Block (SMB) protocol is used by the Nutanix Files service to provide file-level storage to clients, not for presenting block or VM storage to an ESXi hypervisor.

1. Nutanix University. (2022). Nutanix Hybrid Cloud Fundamentals v6.5 Student Guide. Module 2: Nutanix Cluster Architecture, Section: "Controller VM (CVM)", Page 2-11. The guide states, "For vSphere, the CVM presents storage to the hypervisor using NFS."

2. Nutanix. (2023, December). Best Practices Guide for VMware vSphere on Nutanix. Section: "Nutanix Storage for vSphere". This document specifies, "The Nutanix cluster exports a single, large NFS datastore to the vSphere cluster... The datastore is presented to each ESXi host in the vSphere cluster from the local Controller VM (CVM) over a 10 GbE vSwitch."

3. Poitras, S. (2023). The Nutanix Bible. Section: "Architecture", Chapter: "I/O Path Deep Dive". The text clarifies the storage presentation method: "The Nutanix CVM presents storage to the hypervisor via NFS (for vSphere) or iSCSI (for Hyper-V/XenServer) or natively for AHV."