Hardware terminology

Learn how the hardware terms apply to your storage array.

Component Description
Storage array A storage array includes the shelves, controllers, drives, software, and firmware.
Shelf A shelf is an enclosure installed in a cabinet or rack. It contains the hardware components for the storage array. There are two types of shelves: a controller shelf and a drive shelf. A controller shelf includes controllers and drives. A drive shelf includes input/output modules (IOMs) and drives.
Controller A controller consists of a board, firmware, and software. It controls the drives and implements the System Manager functions.
Drive A drive is an electromagnetic mechanical device that provides the physical storage media for data.
Bay A bay is a slot in the shelf where a drive or other component is installed.
Drive shelf A drive shelf, also called an expansion shelf, contains a set of drives and two input/output modules (IOMs). The IOMs contain SAS ports that connect a drive shelf to a controller shelf or to other drive shelves.
Controller shelf A controller shelf contains a set of drives and one or more controller canisters. A controller canister holds the controllers, host interface cards (HICs), and batteries.
Power/fan canister A power/fan canister is an assembly that slides into a shelf. It includes a power supply and an integrated fan.
IOM (ESM) An IOM is an input/output module that includes SAS ports for connecting the drive shelf to the controller shelf.
Note: In previous controller models, the IOM was referred to as an environmental service module (ESM).
SFP An SFP is a Small Form-factor Pluggable (SFP) transceiver.