NCA 6.10 · Reference

Glossary

The terms the NCA tests directly, defined and verified against Nutanix documentation. For the full curriculum glossary see Appendix A.

AOSAcropolis Operating System: The core Nutanix software that runs the Distributed Storage Fabric and cluster services. Upgraded via LCM; Prism Element is built into it.
AHVAcropolis Hypervisor: Nutanix's built-in, KVM-based hypervisor, included free in every NCI license. The default hypervisor; Nutanix also supports ESXi and Hyper-V.
CVMController VM: A VM on every node that runs AOS storage services (the DSF) and presents pooled storage to the hypervisor. Prism Element runs inside it.
DSFDistributed Storage Fabric: The software-defined storage layer that pools all disks across nodes and serves them to VMs, with data locality.
Storage pool: All physical disks across all nodes pooled together. Usually one per cluster; it is raw capacity, not where policy is set.
Storage container: A logical slice of the storage pool where you set policy: Replication Factor, compression, deduplication, and erasure coding. Presented to the hypervisor as a datastore/share.
vDisk: A virtual disk a VM consumes, living inside a container; distributed across the cluster as extents.
Replication FactorRF: How many copies of data a container keeps. RF2 = 2 copies (min 3 nodes); RF3 = 3 copies (min 5 nodes). Set on the container.
Redundancy Factor / Fault ToleranceFT: Cluster-level resiliency. FT1 (data RF2) tolerates 1 failure; FT2 (data RF3) tolerates 2. Default is RF2/FT1.
Compression: Storage optimization using LZ4/LZ4HC, inline for large/sequential I/O (over 64 KB) or post-process. The broadly safe default.
Deduplication: Removes duplicate data blocks using SHA-1 fingerprints; best for VDI and full clones. Inline and post-process.
Erasure CodingEC-X: RAID-like parity striped across nodes for capacity savings on cold data; post-process on data write-cold for more than 7 days.
Prism ElementPE: The per-cluster management UI built into AOS, running in every CVM. Manages only its own cluster; upgrades with AOS.
Prism CentralPC: A separately deployed VM (or scale-out VM cluster) that manages many clusters across sites; its own upgrade path; enables Categories.
LCMLife Cycle Manager: One-click, dependency-aware updater for cluster software and firmware. Run Inventory first; supports dark sites via a local bundle.
NCCNutanix Cluster Check: The health-check framework that scans configuration, performance, and operation. Run with ncc health_checks run_all or from Prism.
Pulse: Proactive telemetry that securely sends cluster health/config data to Nutanix on a schedule; packaged with NCC; feeds Insights.
Insights: Nutanix's predictive-health and support-automation platform, fed by Pulse data.
Foundation: The tool that images bare-metal nodes with AOS and a hypervisor and forms a cluster; built into CVMs; needs ~3 IPs per node.
NGTNutanix Guest Tools: In-guest agent enabling application-consistent (VSS) snapshots, Self-Service/File-Level Restore, and VirtIO mobility drivers.
ADSAcropolis Dynamic Scheduling: Automatic, on-by-default scheduler that balances VM placement to avoid hot spots (the AHV analog of VMware DRS).
VM High AvailabilityHA: Restarts VMs on surviving hosts after an unplanned host failure (a restart, not a live move).
Live Migration: Planned, no-downtime move of a running VM between hosts; memory state copies while the VM runs.
Witness VM: An external arbiter in a separate failure domain required by two-node (and used by Metro) configurations to preserve resiliency.
Protection DomainPD: A group of VMs/volume groups snapshotted and replicated together on a schedule. A consistency group is a crash-consistent subset of a PD.
Async / NearSync / Metro: Replication tiers by RPO: Async ≥ 60 min; NearSync 1-15 min; Metro Availability is a synchronous stretched cluster with RPO 0.
OVSOpen vSwitch: The AHV virtual switch. Default bridge br0, default uplink bond br0-up; CVM and host on the native VLAN.
NC2Nutanix Cloud Clusters: The full Nutanix stack (CVM, AHV, AOS, Prism) running on bare-metal instances in AWS and Azure, operated as one cloud with on-prem.
NCINutanix Cloud Infrastructure: The core platform licensing that includes AOS and AHV, sold in Starter, Pro, and Ultimate tiers.