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. |