Data ONTAP storage architecture overview

Storage architecture refers to how Data ONTAP provides data storage resources to host or client systems and applications. Data ONTAP distinguishes between the physical layer of data storage resources and the logical layer.

The physical layer includes disks, Redundant Array of Independent Disks (RAID) groups they are assigned to, plexes, and aggregates.
The logical layer includes the file systems— volumes, qtrees, Logical Unit Numbers (LUNs)— and the directories and files that store data.

Aggregates provide storage to volumes. Aggregates are made up of sets of disks, which Data ONTAP automatically organizes into one or more RAID groups. Aggregates have one or two plexes, depending on whether RAID-level mirroring (SyncMirror), is in use.

Volumes are data containers. Clients can access the data in volumes through the access protocols supported by Data ONTAP. These protocols include Network File System (NFS), Common Internet File System (CIFS), HyperText Transfer Protocol (HTTP), Web-based Distributed Authoring and Versioning (WebDAV), Fibre Channel Protocol (FCP), and Internet SCSI (iSCSI).

You can partition volumes and control resource usage using qtrees. You can create LUNs for use in a SAN environment, using the FCP or iSCSI access protocols. Volumes, qtrees, and LUNs contain directories and files.

Note: Starting in Data ONTAP 7.3, V-Series systems also support native disk shelves on some V-Series models as part of its storage pool. See the V-Series Implementation Guide for Native Disk Shelves for more information.

Related concepts

How Data ONTAP works with disks

How Data ONTAP uses RAID to protect your data and data availability

How aggregates work

Related information

Data ONTAP Information Library