How ONTAP reports disk types

ONTAP associates a type with every disk. ONTAP reports some disk types differently than the industry standards; you should understand how ONTAP disk types map to industry standards to avoid confusion.

When ONTAP documentation refers to a disk type, it is the type used by ONTAP unless otherwise specified. RAID disk types denote the role that a specific disk plays for RAID. RAID disk types are not related to ONTAP disk types.

For a specific configuration, the disk types that are supported depend on the storage system model, the shelf type, and the I/O modules that are installed in the system.

The following tables show how ONTAP disk types map to industry standard disk types for the SAS and FC storage connection types, and for storage arrays.

SAS-connected storage

ONTAP disk type Disk class Industry standard disk type Description
BSAS Capacity SATA Bridged SAS-SATA disks with added hardware to enable them to be plugged into a SAS-connected storage shelf
FSAS Capacity NL-SAS Near Line SAS
MSATA Capacity SATA SATA disk in multi-disk carrier storage shelf
SAS Performance SAS Serial-Attached SCSI
SSD Ultra-performance SSD Solid-state drives

FC-connected storage

ONTAP disk type Disk class Industry standard disk type
ATA Capacity SATA
FCAL Performance FC

Storage arrays

ONTAP disk type Disk class Industry standard disk type Description
LUN N/A LUN Logical storage device that is backed by storage arrays and used by ONTAP as a disk

These LUNs are referred to as array LUNs to distinguish them from the LUNs that ONTAP serves to clients.