Glossary
QX and QXS Setup Guide
206
drive enclosure
A drive enclosure (expansion chassis) that contains two expansion I/O modules. The
expansion chassis can be connected to a RAID expansion to provide additional storage
capacity.
dual-port drive
A drive that is connected to both controllers so its data path is fault-tolerant.
Dynamic Host
Configuration
Protocol
See DHCP.
EC
Expander Controller. A processor, located in the SAS expander in each controller module and
expansion module, that controls the SAS expander and provides SES functionality. See also
EMP, MC, and SC.
electromagnetic
interface
See EMI.
EMI
Electromagnetic interface.
EMP
Enclosure management processor. An EC subsystem that provides SES data such as
temperature, PSU and fan status, and the presence or absence of drives.
enclosure
Called a RAID chassis (containing controllers) or an expansion chassis (containing I/O
modules). A physical storage device that contains drives and other FRUs.
enclosure
management
processor
See EMP.
Expander
Controller
See EC.
expansion
chassis
See drive enclosure.
expansion I/O
module
A FRU that contains the following subsystems and devices: a SAS expander and EC
processor; host, expansion, and service ports; and midplane connectivity. In a 2U12, 2U24, or
2U48 expansion chassis, the upper expansion module is designated
A
and the lower one is
designated
B
.
FC-AL
Fibre Channel Arbitrated Loop. The FC topology in which devices are connected in a one-way
loop.
Fibre Channel
Arbitrated Loop
See FC-AL.
field-
programmable
gate array
See FPGA.