Glossary
35
Nexsan
www.nexsan.com
Nexsan E60™/Nexsan E48™
FRU Removal and Replacement Guide
M
Mb
Megabit. Approximately one million (1,000,000)
bits.
Mb/s
Megabits (Mb) per second. Used to describe the
speed of network data transmission.
P
PCIe
Peripheral Component Interconnect Express. A
computer expansion card standard designed to
replace the older Peripheral Component
Interconnect (PCI), PCI-eXtended (PCI-X), and
Accelerated Graphics Port (AGP) standards.
pod
See active drawer.
power supply unit
A module that regulates electrical power to the
components of Nexsan storage units.
PSU
See power supply unit.
R
rack
A metal frame designed to hold hardware
devices.
rack-mounted
Attached to a rack.
rack mount
Hardware for attaching devices to a rack.
RAID
Redundant Array of Independent Disks. A
system using multiple hard drives organized into
a single logical unit for the sharing or replication
of data in order to increase data integrity, fault-
tolerance, and throughput. Also referred to as a
RAID set. RAIDs are organized into
RAID levels, which describe their architecture
and configuration.
RAID Controller
A hardware device, software program, or
combination of the two which manages the
physical disk drives in a RAID and presents
them as a single logical unit to attached devices.
The RAID Controllers in Nexsan storage units
are hardware modules. Nexsan RAID
Controllers also provide connections for system
administration and configuration.
RAID level
A numeric indicator of the architecture used by a
RAID. RAIDs can be built using any combination
of striping, mirroring, and parity. The levels are
numbered from 0 through 6. Some RAID levels
can also be combined, and these configurations
are usually referred to with a two-digit number.
For example, RAID 10 = RAID 1 + RAID 0.
rail
A type of rack mount that allows a device to be
easily slid into and back out of a rack.
S
SAN
See storage area network.
SAS
Serial Attached SCSI. A serial version of the
SCSI interface. A point-to-point architecture that
uses a disk controller with four or more channels
that operate simultaneously. Each full-duplex
channel, known as a SAS port, transfers data at
1.5Gb/s, 3Gb/s, or 6Gb/s in each direction. SAS
also supports Serial ATA (SATA) drives, which
can be mixed with SAS drives in a variety of
configurations.
SATA
Serial Advanced Technology Attachment. A
connection standard for fixed and removable
hard disk drives.
SCSI
Small Computer System Interface. A collection
of standards and proposed standards for
input/output (I/O) communication, primarily