NetApp ONTAP glossary

A

alias

A second name for a feature object, such as a CIFS NetBIOS server name, tape device, or FC WWPN. ONTAP 9.19.1 does not document a general administrator command-alias facility; keep CLI shortcuts in the calling shell. See CLI scripting.

aggregate

The physical storage pool: one or more RAID groups of disks (or an all-flash pool) formatted as a single WAFL filesystem. Aggregates own the raw space; volumes are created inside them. See WAFL deep-dive.

AFF

All-Flash FAS — NetApp's all-NVMe/all-SSD platform line. Same ONTAP, no spinning disks, designed for low latency and high IOPS.

AIPod

NetApp's prevalidated AI infrastructure stack pairing NVIDIA accelerated compute (DGX-class) with NetApp AFF all-flash storage running ONTAP, designed to start small and scale without redesigning the data layer. AIPod Mini is the Intel Xeon/Gaudi variant for departmental and edge AI.

ARP (Autonomous Ransomware Protection)

ONTAP's on-box ransomware detection: it learns a volume's normal file-activity baseline, then watches for mass-encryption patterns and automatically creates a recovery snapshot when an attack is suspected. See the Autonomous Ransomware Protection & Cyber Vault guide and security hardening checklist.

ASA

AFF SAN Array — an AFF system locked into SAN-only mode (no NAS protocols, no SVMs in the usual sense). Simplifies FC/NVMe-over-FC deployments; storage is presented as LUNs only.

AUSO

Automatic Unplanned Switchover — the MetroCluster feature that lets the surviving site take over automatically after a site failure, with the mediator's vote.

AutoSupport

ONTAP's built-in health telemetry: periodic and event-triggered messages sent to NetApp (or your own mail server) so support can see the system's state before you open a case. See the AutoSupport, EMS & Active IQ guide.

autodelete (Snapshot)

An ONTAP volume policy that can delete eligible snapshots when configured space-pressure triggers are reached. Review the trigger, target, commitment and deletion order before enabling it; see common space mistakes.

audit log

Evidence of selected data-access or management activity. ONTAP writes SVM NAS audit records to rotated EVTX/XML files and keeps administrative requests in the cluster security audit log. See the audit & event logging guide.

adaptive QoS

A QoS mode where performance ceilings scale automatically with storage size, rather than being fixed numbers you set once.

Azure NetApp Files (ANF)

Microsoft's first-party managed file service in Azure. Capacity is provisioned as pools with service levels; volumes are managed through Azure APIs rather than an ONTAP cluster CLI. See the ANF guide and cloud decision guide.

Astra Control

NetApp's application-aware data management suite for Kubernetes (Astra Control Center on-prem, Astra Control Service in cloud). Orchestrates app-consistent backups, snapshot schedules, and cross-cluster disaster recovery powered by ONTAP and SnapMirror. See the Trident & Kubernetes guide.

ALUA

Asymmetric Logical Unit Access — the SCSI T10 multipath standard ONTAP uses for SAN LUNs in an HA pair: each host path is marked active-optimized (through the LUN's home node) or active-non-optimized (partner node via cluster interconnect). See the SAN & multipathing guide.

ANA

Asymmetric Namespace Access — the NVMe-oF multipathing specification (equivalent to SCSI ALUA) used in NVMe/FC and NVMe/TCP to report optimized, non-optimized, and inaccessible namespace path states to hosts.

Active IQ

NetApp's cloud digital advisor, which analyzes AutoSupport telemetry for risks, capacity trends, upgrade recommendations, and support insights.

aggregate hot spot

An aggregate whose disks or controller path are disproportionately busy, making it a bottleneck while capacity or performance remains available elsewhere.

Ansible collection

The netapp.ontap automation modules used to configure and operate ONTAP through REST or legacy ONTAPI.

auto-giveback

An HA setting that returns aggregates to their home node automatically after recovery and safety checks. See the HA pairs guide.

autosize

A FlexVol policy that grows a volume, or grows and shrinks it, when used-space thresholds are crossed within configured minimum and maximum sizes. See the FlexVol guide.

AutoSupport invoke

A manually triggered AutoSupport message, commonly used to test delivery or send a user-defined support notification.

B

broadcast domain

The grouping of network ports that share L2 reachability and MTU; ONTAP uses it for LIF placement and failover. See network architecture.

break (SnapMirror)

Stopping replication so the destination can be written to independently — the first step of an unplanned failover. Re-establish with a resync afterwards.

BlueXP

NetApp's SaaS control plane (bluexp.netapp.com) for managing on-prem ONTAP clusters and cloud storage — Cloud Volumes ONTAP, FSx for ONTAP, Azure NetApp Files — from one dashboard. Free to use; you pay for the storage systems it manages. See the BlueXP guide.

boot menu

A node-console startup menu for maintenance and recovery operations such as booting an alternate image, initializing disks, or entering maintenance mode.

bucket

The top-level S3 object container exposed by ONTAP, with its own capacity and access policy. See the ONTAP S3 guide.

C

CHAP

Challenge-Handshake Authentication Protocol, used to authenticate an iSCSI initiator to an ONTAP target; mutual CHAP authenticates both directions. See the iSCSI guide.

cluster

The whole ONTAP system: two or more nodes (up to 24 in a cluster) that share management, SVMs, and a unified namespace.

capacity pool (ANF)

In Azure NetApp Files, the provisioned block of billed capacity with a fixed service level (Standard/Premium/Ultra) that determines per-TiB throughput. Volumes are carved out of a pool. See the ANF guide.

Cloud Volumes ONTAP (CVO)

ONTAP packaged as VMs that run in AWS, Azure, or GCP on standard compute. You operate it like on-prem ONTAP (full CLI, node shell) and typically deploy it via BlueXP. The middle ground between fully managed (FSx/ANF) and buying hardware. See the BlueXP guide.

cluster peering

A trust relationship between two ONTAP clusters that enables cross-cluster data movement: SnapMirror, SnapVault, SVM DR, and FlexCache. Uses Intercluster LIFs (IC-LIFs), full-mesh TCP/10000 communication, and TLS in-flight encryption. See the Cluster & SVM Peering guide.

CIFS

The older name for SMB file sharing, still used in ONTAP for SMB server objects (vserver cifs). SMB 3.x is the modern protocol version.

SMB Multichannel

SMB 3.x feature (enabled by default on ONTAP) where a client session uses multiple TCP connections — one per client/server NIC pair — to aggregate bandwidth and survive NIC failure. Verify with vserver cifs session show -fields connection-count.

continuously available (CA) share

An SMB 3 share marked continuously-available that survives ONTAP takeover/giveback via persistent handles — required for Hyper-V and SQL Server over SMB. Requires the CA license and a CA-aware client.

consistency point (CP)

The moment WAFL atomically flips its root pointer, committing batched writes to disk. The filesystem is always consistent because states change only at CPs.

consistency group (CG)

A named group of volumes that ONTAP snapshots as one unit, so every member volume is captured at the same instant — how multi-volume applications (Oracle, SAP HANA, VMware datastores) avoid torn writes across members. Managed with volume consistency-group commands, SnapCenter, or BlueXP. See the SnapCenter guide.

constituent

One of the FlexVols that make up a FlexGroup. Files are distributed across constituents; each lives on its own aggregate.

copy-on-write (CoW)

WAFL's rule that changed blocks are written to new locations rather than overwritten in place — what makes snapshots and clones nearly free. See the deep-dive.

cloud tiering (FabricPool)

Moving cold blocks of a volume to object storage (S3, Azure Blob, Google Cloud, StorageGRID) while hot blocks stay on local flash. The volume still looks and behaves like one filesystem. See the FabricPool deep-dive.

compression

Storage efficiency: compressing data blocks to reduce physical footprint. ONTAP does inline (at write time) and post-process (background) compression.

callhome

A legacy operational term for an AutoSupport notification sent off-cluster when ONTAP detects a significant event.

CBL (capacity-based licensing)

A model that meters protected or managed capacity rather than licensing each controller or feature individually. See the licensing guide.

capacity unit

A metered quantity of storage used for subscription, service-level, or licensing calculations; its exact scope depends on the offering.

CFE

Common Firmware Environment — the low-level boot firmware and console environment used by many ONTAP hardware platforms.

cluster management LIF

The floating administrative IP used to manage the whole cluster; it can migrate between nodes independently of data LIFs.

compaction

A storage-efficiency technique that packs multiple small compressed data blocks into one 4 KiB physical block.

ComplianceClock

SnapLock's tamper-resistant time base for retention expiry; it cannot be moved backward. See the SnapLock guide.

counter manager

The ONTAP subsystem that organizes performance objects, instances, and counters consumed by statistics commands and monitoring tools. See performance counter concepts.

D

dNFS (Oracle Direct NFS)

Oracle's database-integrated NFS client, which can manage NFS paths and I/O independently of the host kernel client. Validate protocol and mount settings for the certified Oracle/ONTAP stack; see databases on ONTAP.

DDP (Dynamic Disk Pools)

SANtricity pool layout that distributes data, parity, and preservation capacity across the participating drives instead of using fixed RAID groups and dedicated spares. See the E-Series & EF-Series guide.

deduplication

Storage efficiency: replacing duplicate blocks with pointers to a single shared block. Most effective for virtual machine disks and copies of the same data.

destination volume

The replica side of a SnapMirror relationship — read-only during normal replication, writable once you break the relationship.

disk ownership

Which node in the HA pair owns a given disk. Disks can be moved between partners; ownership is what lets takeover/giveback work.

data protection (DP)

The volume type used for SnapMirror/SnapVault destinations. DP volumes exist only to hold replicas and aren't directly mounted.

disaster recovery

The set of processes and technologies (SnapMirror, MetroCluster, SVM DR) that keep data available after a site or system loss. See MetroCluster.

disk shelf

The physical enclosure holding disks, attached to nodes via SAS or NVMe cabling. Shelves provide power, cooling, and the disk-to-node connections.

Disk Qualification Package (DQP)

An ONTAP package containing supported-drive identification and qualification data, updated when newly qualified disks must be recognized.

E

E-Series

NetApp's SAN-focused block-storage family running SANtricity OS rather than ONTAP; EF-Series denotes flash-focused models. See the E-Series & EF-Series guide.

EMS

Event Management System — ONTAP's on-cluster event stream, with severity filtering and destinations such as syslog, SNMP, and email. See the AutoSupport, EMS & Active IQ guide.

EMS

Event Management System — ONTAP's event bus. Everything notable becomes an EMS event you can see with event log show, filter, and alert on.

export policy

The NFS access-control list attached to volumes and qtrees: rules saying which clients can mount with which permissions. See the NFS deep dive and first-day example.

root squash

Export-rule behavior controlled by -superuser: squashing maps the NFS root user to nobody so remote root cannot act as Unix root on the volume. -superuser any disables it (needed for some installers); the secure default for file shares is none or a Kerberos flavor.

storage efficiency

The umbrella term for deduplication, compression, compaction, and thin provisioning — all the features that make data take less physical space.

NVE (NetApp Volume Encryption)

Software encryption at individual-volume scope, with a unique data-encryption key per encrypted volume. See the encryption deep dive.

NAE (NetApp Aggregate Encryption)

Software encryption using an aggregate-level key; new volumes in an NAE aggregate are encrypted by default. See the encryption deep dive.

NSE (NetApp Storage Encryption)

At-rest encryption performed by supported self-encrypting drives, distinct from software NVE/NAE. See the encryption deep dive.

effective capacity

The logical data a system can hold after applying an assumed or measured efficiency ratio to usable physical capacity. It is workload-dependent, not guaranteed; see capacity planning.

Event-Based Retention (EBR)

A SnapLock capability that starts a file's retention period when an application-defined event occurs instead of at commit time.

EVTX

The Windows Event Log format ONTAP can use for consolidated SMB and NFS audit records.

/etc/hosts (static hosts)

The familiar name for ONTAP's per-SVM static host table, managed with vserver services name-service dns hosts commands and selected through the files source. See the static hosts runbook.

F

FAS

NetApp's hybrid platform line — Flash + spinning disk (or all-flash configurations). The general-purpose ONTAP systems. AFF is the all-flash member of the family.

FSx for ONTAP

AWS's managed ONTAP file service inside a VPC, exposing SVM, volume, snapshot, and supported SnapMirror capabilities within service limits. See the FSx guide and cloud decision guide.

FabricPool

NetApp's automated cloud tiering feature: moves cold blocks to S3, Azure Blob, GCS, or StorageGRID. See the FabricPool guide and cloud tiering.

storage failover (SFO)

The HA mechanism where a partner node takes over a failed node's storage (takeover) and later returns it (giveback). Lossless thanks to the NVRAM mirror.

foreign disk / aggregate

A disk or aggregate whose ownership belongs to a different cluster (e.g. used gear from a decommissioned system). Foreign disks show as unowned until reassigned — see the decommissioning runbook and aggregate-offline triage.

FlexCache

A read cache volume that mirrors a subset of a source volume onto other nodes, so remote sites serve their own reads instead of hitting the origin. Full runbook: FlexCache on ONTAP.

FlexClone

An instant, writable copy of a volume (or file/LUN) that shares blocks with its parent snapshot until it writes its own. See the deep-dive.

FlexPod AI

NetApp's joint converged-infrastructure design with Cisco for AI workloads: Cisco UCS servers, NVIDIA GPUs, and Cisco Nexus networking combined with NetApp AFF A-Series/C-Series storage running ONTAP, validated for enterprise generative AI and LLM fine-tuning.

FlexGroup

ONTAP's scale-out NAS volume: one namespace striped across many constituent FlexVols on different nodes. See the FlexGroup deep-dive.

FlexVol

The standard ONTAP volume: a flexible, resizable logical container in an aggregate, with its own snapshots, quota rules, and settings. See the FlexVol deep dive.

FPolicy

ONTAP's external file-policy notification engine: selected NFS/SMB operations are sent to policy servers for screening, compliance, auditing, or orchestration. See the FPolicy guide.

Fibre Channel (FC)

The classic SAN transport. ONTAP uses FC for LUNs and NVMe-over-FC, and FC (or IP) between MetroCluster sites.

Flash Cache

A read cache card in a hybrid system that accelerates reads of hot data without moving it to flash permanently.

fractional reserve

Aggregate space reserved for overwrites to blocks protected by snapshots, historically important for guaranteed-space SAN volumes. See FlexVol space guarantees.

G

giveback

Returning storage from the takeover partner to the original node after maintenance or a failure — the second half of storage failover.

space guarantee

A volume's physical-capacity commitment: volume reserves its size, none thin-provisions it, and legacy file behavior depends on platform and release. See FlexVol space guarantees.

Google Cloud NetApp Volumes (GCNV)

Google Cloud's fully managed file-storage service with pools, service levels, and volumes managed through Google Cloud APIs rather than an ONTAP cluster CLI. See the GCNV guide and cloud decision guide.

H

HA pair

Two nodes connected by an HA interconnect, each able to take over the other's storage using mirrored write intent. The fundamental ONTAP availability unit; see the takeover and giveback guide.

hybrid aggregate

An aggregate mixing flash and spinning disk, letting ONTAP tier hot data to flash automatically within the aggregate.

I

inode

The on-disk structure describing a file or directory: its blocks, ownership, permissions, timestamps. Running out of inodes means running out of files, even with free capacity.

iSCSI

SAN protocol carrying SCSI over TCP/IP. ONTAP serves mapped LUNs through SVM target LIFs. See the iSCSI guide.

IQN

iSCSI Qualified Name, the persistent text identifier for an iSCSI initiator or target. See the mapping runbook.

HA interconnect

The dedicated link(s) between HA pair nodes carrying NVRAM mirror traffic and heartbeat — the backbone of takeover.

ILM

Information Lifecycle Management — the policy engine in StorageGRID that decides how many object copies exist, where (which sites/tiers), and for how long. See StorageGRID: object platform.

IPspace

An isolated ONTAP network domain containing its own SVM networking, routes, and broadcast domains, including support for overlapping addresses. See network architecture.

identity-preserve

An SVM DR option that replicates SVM identity and configuration so the destination can assume it during failover. See the SVM DR guide.

igroup

Initiator group — host FC WWPNs, iSCSI IQNs, or other initiators to which ONTAP maps LUNs. See iSCSI provisioning.

intercluster LIF

A LIF dedicated to cross-cluster traffic such as SnapMirror, SVM DR, and FlexCache.

J

job schedule

A named cron or interval schedule consumed by ONTAP features such as snapshot policies. It does not execute an arbitrary CLI command by itself. See schedules and jobs.

junction path

The mount point of a volume in an SVM's namespace, e.g. /data/projects. The junction makes volumes visible to NAS clients. See FlexVol junctions and first-day provisioning.

K

Keystone

NetApp's Storage-as-a-Service subscription: customers commit capacity by performance service level and pay for metered burst above that baseline. See the Keystone guide.

Kerberos

The authentication protocol used for secure NFS (krb5/krb5i/krb5p) and SMB. ONTAP authenticates users against Active Directory/KDC via its Kerberos service.

KMIP

Key Management Interoperability Protocol, used by ONTAP to communicate with supported external key-management servers. See the encryption guide.

onboard key manager (OKM)

ONTAP's in-cluster key manager, protected by a cluster-wide passphrase and recoverable backup material. See the encryption guide.

L

licensing

ONTAP entitlement through legacy controller-bound feature packages or modern capacity-based licenses with capacity, subtype, and optional term dates. See the ONTAP licensing guide.

LIF (logical interface)

A logical network endpoint with an address, service policy, home node, and home port; eligible LIFs can migrate or fail over. See the LIF deep dive.

LUN

A block device carved from a volume and presented over FC/iSCSI/NVMe. LUNs are what SAN hosts (VMware, Windows, Linux) see as disks.

LDAP

A directory protocol ONTAP can use to resolve UNIX users and groups for NAS permissions. See NAS identity and LDAP.

latency

Response time of an I/O operation. ONTAP keeps client-visible latency low by acknowledging writes from NVRAM and batching disk flushes.

LACP

Link Aggregation Control Protocol — used with dynamic multimode interface groups to bundle Ethernet links.

legal hold

A SnapLock control that prevents selected WORM files from expiring until every applied hold is released.

License-as-a-Service

A subscription entitlement in which software rights are renewed as a service rather than installed as perpetual controller-bound licenses.

lifecycle policy

Rules that transition or expire objects based on age or other criteria, automating bucket-object retention actions.

LIF failover group

A named set of network ports that an eligible LIF may use when its home port or node is unavailable. See failover groups and policies.

load-sharing mirror

A read-only mirror of an SVM root volume that distributes namespace access and protects against loss of the root volume.

M

MetroCluster

NetApp's stretch-cluster DR solution: two sites, synchronous mirroring, and supported switchover automation. See the MetroCluster guide and DR comparison.

mediator

A lightweight witness service deployed in a third failure domain for MetroCluster IP and SnapMirror Active Sync / SM-BC. Provides independent quorum arbitration to safely trigger automated zero-touch failover without risk of split-brain. See the SnapMirror Active Sync guide and MetroCluster guide.

multi-admin verification

A 9.9+ ONTAP control that requires a second (or third) approver before destructive commands run — cluster image update, volume delete, SnapMirror break, RBAC changes. A stolen single admin credential can no longer destroy a cluster. See the security hardening checklist.

SnapMirror

ONTAP's replication engine: asynchronous or synchronous copies of volumes/consistency groups to another location, using snapshots as the transfer unit. See the SnapMirror async replication guide.

SnapMirror Sync

Synchronous SnapMirror replication that commits protected writes to source and destination for a zero-data-loss recovery point while the relationship is in sync. Activation and application recovery still require a runbook; see the DR strategy comparison.

SMB over QUIC

SMB wrapped in TLS 1.3 QUIC transport on UDP 443, letting remote clients reach shares without a VPN. ONTAP enables it per-SVM with a server certificate. See the SMB over QUIC guide.

SnapMirror Active Sync (SM-AS / SM-BC)

Zero RPO and zero RTO synchronous replication with automated, storage-side failover via ONTAP Mediator. Protects SAN LUNs and NAS volumes across metro distances with uniform multipathing. See the SnapMirror Active Sync guide.

SnapVault

Disk-to-disk backup flavor of SnapMirror: keeps many point-in-time snapshots on the destination with different retention than the source.

maintenance mode

A special boot environment for low-level disk, aggregate, and HA operations unavailable from the normal clustered shell.

N

NFSv4.1

A stateful NFS version with sessions and integrated locking; pNFS support depends on client and ONTAP release. See the protocol guide.

namespace

Context matters: in NAS, the tree of junction paths visible from an SVM root; in NVMe-oF, a host-visible block device created inside a volume or qtree and mapped through one subsystem. See the NVMe-oF guide.

NFS

The Unix file-sharing protocol. ONTAP supports NFSv3, NFSv4.0/4.1 (with pNFS), and exports with granular export policies.

NFSv4 ACL

Granular per-user/per-group access-control entries over NFSv4, stored by ONTAP as NTFS ACLs — so they need NTFS/mixed security style plus working identity mapping. See the NFSv4 ACL migration guide.

NVRAM/NVMEM

The non-volatile write log that makes acknowledged writes durable and takeover lossless. See the NVRAM deep-dive.

NVMe

The modern storage command set: NVMe over Fabrics (FC or TCP) for SAN, and the media type inside AFF systems.

NVMe-oF

NVMe over Fabrics — transports the NVMe command set between a host and remote namespaces. ONTAP supports NVMe/FC and NVMe/TCP with native ANA multipathing. See the NVMe over Fabrics guide.

node

One controller (hardware + ONTAP instance) in a cluster. Nodes come in HA pairs and share the cluster's SVMs and volumes.

NDMP

The protocol ONTAP uses for tape-based backup: dump/restore streams to NDMP-capable backup software, often from snapshots for consistency.

NIS

Legacy UNIX directory service that ONTAP can query for NAS identities. See NAS identity and NIS.

name mapping

Ordered per-SVM regular-expression rules that translate Windows, UNIX, Kerberos or S3 identities in a specified direction. See the name-mapping guide.

NTLM

A Windows challenge-response authentication family used when Kerberos is unavailable. NTLMv1 is obsolete and should not be permitted; validate client dependencies before tightening SMB authentication. See common security mistakes.

name service switch

The per-SVM lookup order for hosts, users, groups, netgroups and name mappings across files, DNS, LDAP or NIS. See the time and name services guide.

NTP

Network Time Protocol, used by ONTAP nodes to synchronize the cluster clock with external time sources. See the NTP runbook.

nconnect

Linux NFS client mount option that opens multiple TCP connections per mount (up to 16), beating single-flow throughput limits against arrays like ONTAP. Common values 4–8; tune per workload.

NAS

Network-attached storage serving file protocols such as NFS and SMB, in contrast with block-oriented SAN access.

NetApp Console

NetApp's unified web management experience for storage and data services across on-premises and cloud environments.

node management LIF

A non-floating administrative IP tied to one node for direct management and troubleshooting.

NVMe/FC

NVMe over Fibre Channel, preserving FC zoning and multipathing. See the NVMe-oF guide.

NVMe/TCP

NVMe over standard TCP/IP Ethernet, providing low-overhead block access without Fibre Channel. See the NVMe-oF guide.

NVMe namespace

The logical block device presented by an NVMe subsystem, analogous to a SCSI LUN.

O

ONTAP Simulator

A virtual ONTAP environment for learning management and data-service workflows without controller hardware. Availability, licensing, and limits vary; see the lab guide.

ONTAP

NetApp's storage operating system, running on FAS/AFF systems, ONTAP Select (software), and in the cloud (FSx for ONTAP, Azure NetApp Files, Google Cloud NetApp Volumes).

ONTAP AI

NetApp's family of validated reference architectures that pair NVIDIA accelerated compute with NetApp storage, so ONTAP data services (snapshots, clones, replication, tiering, multi-protocol access) serve AI training, RAG, and inference pipelines.

ONTAP Select

ONTAP as software on supported ESXi or KVM servers for edge, ROBO and software-defined storage. See the ONTAP Select & edge guide.

ONTAP Edge

A shorthand often used for ONTAP at an edge site. Data ONTAP Edge was a legacy virtual appliance; it is not a current free ONTAP edition. Current deployments use ONTAP Select.

ONTAP Tools for VMware vSphere

The unified VMware plug-in appliance (successor to Virtual Storage Console) bundling array management, the VASA provider for VVols, and the SRA for Site Recovery Manager. See the ONTAP Tools guide.

object store server

ONTAP's built-in S3 service (9.8+): an SVM can present buckets to S3 clients. See the S3 guide.

OneCollect

A NetApp diagnostic utility that gathers host, network, and storage configuration and logs for support analysis.

ONTAP 9.19.1

An ONTAP 9.x release; verify platform support, upgrade paths, and feature availability against its release documentation.

ONTAP Mediator

An external quorum service that helps MetroCluster IP or SnapMirror active sync resolve certain failure scenarios.

ONTAPI version

The compatibility version negotiated by legacy ZAPI clients to determine supported calls and fields.

P

protocol endpoint

A VMware VVol access point that carries I/O to storage objects rather than acting as a conventional shared VMFS LUN. See the VMware guide.

parity

The redundancy math in RAID: parity blocks let the RAID group reconstruct data after a disk failure. RAID-DP uses double parity; RAID-TEC triple.

partition

A slice of a disk with defined ownership. Root-data partitioning splits a disk so each node of an HA pair gets a piece — the foundation of 2-node clusters.

snapshot policy

The named schedule and retention set that drives automatic snapshots on a volume (for example, hourly, daily and weekly copies). See the production protection checklist.

PowerStore (Dell)

Dell's NVMe-native active/active storage appliance line (1200T–9200T / 3200Q) utilizing containerized PowerStoreOS, competing with NetApp AFF and ASA systems. See the NetApp ONTAP vs Dell PowerStore guide.

QoS

Quality of Service: performance ceilings (and floors, with adaptive QoS) applied per volume or workload so noisy neighbors can't starve others. See the QoS policy groups guide.

performance service level

The adaptive-QoS wrapper (Extreme/Performance/Value) that scales IOPS limits with storage size.

performance capacity

An estimate of workload headroom before a node or aggregate resource becomes saturated.

perfstat

A NetApp support tool that captures detailed ONTAP performance counters and configuration over time. See the perfstat collection runbook.

pNFS

Parallel NFS, an NFSv4.1 capability separating metadata coordination from direct data paths for multipath access.

portset

A named subset of SAN target LIFs bound to an igroup to restrict target-port discovery and use.

Protocol Endpoint

A small administrative LUN through which ESXi accesses VVol objects. See the VMware vSphere guide.

Q

quorum

The majority of eligible cluster votes required to maintain authoritative cluster configuration during failures or partitions. Storage takeover is a separate HA-pair mechanism. See cluster quorum.

qtree

A sub-volume directory tree that can have its own quotas, export policies, and security style — a way to carve a volume into independently-managed pieces.

quota

A limit (space and/or file count) applied to users, groups, or qtrees. Quotas enforce capacity discipline per tenant.

QoS policy group

A container applying throughput floors or ceilings to assigned workloads. See the QoS guide.

R

RAID-DP

NetApp's double-parity RAID: survives any two disk failures in a RAID group, and is the default protection level for data aggregates. See RAID and disk management.

RAID-TEC

Triple-parity RAID that survives three concurrent disk failures in a group, trading another drive's capacity for protection. See RAID-TEC versus RAID-DP.

RAID group

A set of disks (data plus parity) that RAID protects as a unit. Aggregates contain one or more RAID groups; see groups and geometry.

REST API (ONTAP)

The JSON-over-HTTPS programmatic interface to ONTAP, under /api/ on the management LIF; ships since ONTAP 9.6 and replaces ZAPI for new automation. See the REST API guide.

root aggregate

The aggregate holding a node's root volume and system configuration—boot-critical storage normally kept separate from data aggregates. See root aggregates.

volume rebalance

Moving files between FlexGroup constituents to even out distribution. Background, throttled, online. See FlexGroup deep-dive.

RPO (Recovery Point Objective)

The maximum acceptable data-loss window measured backward from an incident. It is a service target, not an ONTAP feature; see the DR decision space.

RTO (Recovery Time Objective)

The target time to restore a usable service after disruption. It includes hosts, networks, identity and applications—not just storage failover; see the DR decision space.

snapshot reserve

The percentage of a volume (default 5%) set aside so snapshots don't crowd out live data.

RBAC

Role-based access control — authorization granting users only the CLI commands or REST endpoints required for their role. See administrator RBAC.

S

security style

The UNIX, NTFS or Mixed permission model applied by a volume or qtree. See NAS security styles.

SNMP

Simple Network Management Protocol, used to poll ONTAP MIB objects and deliver traps; ONTAP supports v1, v2c and v3. See monitoring integrations.

syslog

A standard remote event transport that ONTAP EMS notification destinations can use to forward selected events. See EMS syslog forwarding.

service processor (SP/BMC)

The controller's independent out-of-band management processor for remote console, sensors, power control, and recovery when ONTAP networking is unavailable. See SP/BMC administration.

SAML

Security Assertion Markup Language — federation that lets an external identity provider authenticate remote ONTAP web users. ONTAP scope and role-mapping features depend on release; see SAML for System Manager.

SANtricity

The storage operating system and management software for NetApp E-Series and EF-Series arrays, separate from ONTAP. See the SANtricity guide.

SVM (vserver)

Storage Virtual Machine — the tenant/namespace unit of ONTAP: its own protocols, LIFs, volumes, and security. One cluster hosts many SVMs.

SVM peering

An authorized relationship between an SVM on a local cluster and an SVM on a peered remote cluster. Authorizes applications like SnapMirror and FlexCache to replicate volumes across tenant boundaries. See the Cluster & SVM Peering guide.

SVM DR

Disaster recovery for a whole SVM: replicate all its volumes to a peer cluster and fail over the namespace.

SMB

The Windows file-sharing protocol (formerly CIFS). ONTAP supports SMB 3.x features including encryption, multichannel, and continuous availability; check your release. See the SMB guide and protocol comparison.

secure erase

Sanitizing disks before they leave your control — crypto-erase for self-encrypting (NSE) disks, storage disk secure-erase for the rest, or physical destruction. See the decommissioning runbook.

SnapLock

ONTAP's WORM (write-once-read-many) volume type for immutable retention: Compliance (no admin override — regulatory) or Enterprise (admin override allowed). Legal hold can pin files beyond retention. See the SnapLock WORM guide and the security hardening checklist.

S3

The object-storage API. ONTAP 9.8+ speaks S3 natively; see S3 on ONTAP and the S3 troubleshooting runbook.

StorageGRID

NetApp's scale-out object storage platform: a grid of nodes with erasure coding, multi-site ILM policies, and an S3/Swift API — distinct from ONTAP's built-in S3 server. See the StorageGRID guide.

SLM (Selective LUN Map)

An ONTAP SAN optimization that restricts host LUN visibility to only the nodes in the volume's HA pair (the reporting nodes), preventing excessive path counts in large clusters. See the SAN & multipathing guide.

snapshot

A point-in-time, read-only image of a volume, nearly free thanks to copy-on-write. See the deep-dive.

spare disks

The spare pool: owned disks or partitions held outside aggregates so RAID can copy or reconstruct onto compatible capacity after a fault. See spare management.

SyncMirror

Synchronous aggregate mirroring: every write goes to two plexes in separate disk pools, central to MetroCluster and distinct from SnapMirror. See aggregate mirroring.

shelf

See disk shelf.

System Manager

ONTAP's built-in GUI — the browser-based management interface that mirrors most CLI functions.

sysstat

A node-shell real-time summary of ONTAP CPU utilization, operation rates, network and disk throughput, and cache activity. See the monitoring toolkit.

SnapCenter

NetApp's application-aware backup orchestration control plane for databases, VMs, and host file systems using ONTAP snapshots, clones, and secondary SnapMirror copies. See the SnapCenter guide.

subsystem (NVMe)

The NVMe access and discovery boundary that holds authorized host NQNs and namespace mappings. ONTAP generates its NQN; one subsystem can expose several namespaces. See the NVMe-oF guide.

S3 object storage

Storage accessed through S3-compatible HTTP APIs using buckets and object keys. See the ONTAP S3 guide.

SnapDiff

An ONTAP capability that identifies files or directories changed between snapshots for efficient backup scanning.

SnapMirror label

A snapshot label matched by SnapMirror policy rules to select copies for transfer and retention.

SnapRestore

Functionality for rapidly reverting a volume, file, or LUN to snapshot data without copying unchanged blocks.

storage container

The logical pool presented by VASA Provider to vSphere for VVol placement, backed by ONTAP resources.

SP/BMC

The out-of-band Service Processor or Baseboard Management Controller for remote console, power, sensors, and hardware logs.

subnet

An ONTAP object associating an IP range and gateway with a broadcast domain for consistent LIF allocation.

T

Trident (Astra Trident)

NetApp's open-source, dynamic Container Storage Interface (CSI) storage orchestrator for Kubernetes. Translates PersistentVolumeClaims into ONTAP FlexVols, Qtrees, LUNs, and FlexGroups with dynamic provisioning, snapshots, clones, and QoS. See Astra Trident & Kubernetes guide.

TridentBackendConfig (TBC)

A Kubernetes Custom Resource (CRD) used by Astra Trident to define connection credentials, SVM targets, data LIFs, export policies, and storage pool parameters for an ONTAP backend.

takeover

One HA node assuming the failed partner's storage, replaying its NVRAM log and serving its volumes. See NVRAM deep-dive.

thin provisioning

Volumes with space-guarantee none: capacity is claimed virtually and consumed only as data is written. Watch oversubscription.

tiering

Moving blocks between performance tiers (flash ↔ spinning ↔ cloud) automatically based on access temperature.

7-Mode transition

Migration from legacy Data ONTAP 7-Mode to clustered ONTAP using source-version-specific legacy transition procedures and tooling. See migration methods.

transition

7-Mode to cDOT/ONTAP migration (now "ONTAP 9 conversion") — moving legacy 7-Mode systems to clustered ONTAP.

T10-PI

SCSI Protection Information that adds guard, application, and reference tags to detect end-to-end block corruption.

Terraform provider

A plugin that lets Terraform manage NetApp resources as declarative infrastructure.

tiering minimum cooling days

The minimum time blocks must remain cold before FabricPool considers them eligible for the capacity tier.

U

usable capacity

Physical capacity available after drive right-sizing, RAID parity, spares, and ONTAP reservations—before applying storage-efficiency savings. See raw, usable, and effective capacity.

user ID mapping

Translating between Windows SIDs and Unix UIDs/GIDs so mixed NFS+SMB access sees consistent ownership. ONTAP does this via AD/LDAP/NIS lookup.

unified networking

Serving NAS, SAN, and replication over shared Ethernet ports with VLANs/IPspaces — ONTAP's default model on modern platforms.

V

VASA Provider / VSC

VMware storage-awareness services delivered by ONTAP Tools: VASA publishes array capabilities and supports VVols, while VSC is the historical name for the vSphere management plug-in. See the VMware vSphere guide.

VVol

VMware Virtual Volume — a per-VM storage object managed through VASA and accessed through a protocol endpoint instead of a conventional shared VMFS LUN. See the VMware vSphere guide.

volume

The logical container of files/LUNs inside an aggregate: has its own space guarantee, snapshots, quotas, and settings. FlexVol is the standard type. Can be moved non-disruptively across aggregates; see volume move guide.

volume move

ONTAP's non-disruptive storage mobility engine: copies flexible volumes between aggregates or nodes using background SnapMirror replication, cutover hold windows, and automated routing swaps with zero client downtime. See Volume Move guide.

vserver

See SVM.

Vscan

ONTAP's anti-virus framework: file writes are scanned by external AV servers connected over the cluster, blocking or quarantining on detection.

VLAN

Virtual LAN tagging used to split physical ports into multiple networks for different SVMs, IPspaces, or tenants.

VAAI

VMware APIs for Array Integration, offloading cloning, zeroing, and locking to ONTAP. See the VMware vSphere guide.

vsadmin

The predefined SVM administrator role, scoped to one data SVM rather than the entire cluster. See cluster and SVM admin scopes.

W

WAFL

Write Anywhere File Layout — ONTAP's filesystem. Writes land anywhere, metadata is copy-on-write, and state changes atomically at consistency points. See the WAFL deep-dive.

WAFL reserve

The internal space ONTAP keeps for filesystem metadata. In ONTAP 9 it's managed automatically — don't try to reclaim it.

WWPN/WWNN

World Wide Port/Node Names — the unique identifiers of FC ports (and the NVMe equivalents) used for SAN zoning and host mapping.

write-anywhere

WAFL's allocation strategy: new data goes to any free block, enabling write batching, full-stripe RAID writes, and CoW snapshots.

WORM

Write once, read many — committed data cannot be changed or deleted until its retention period expires.

X

XCP

NetApp's file-data migration tool for assessing, copying, synchronizing, and verifying NFS or SMB data at scale. Capabilities and metadata handling differ by protocol and release; see data migration methods.

Z

ZAPI

The legacy XML management API that predates the REST interface; still answered on modern ONTAP for backward compatibility but frozen — new features land as REST endpoints. See the REST API guide.