Glossary
Nexsan E18X and Nexsan E32X
Installation Guide
Nexsan
49
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 sys-
tem 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 com-
bination 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 Systems
are hardware modules. Nexsan RAID Con-
trollers 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 com-
bination 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 enables 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 col-
lection of standards and proposed standards
for input/output (I/O) communication, primarily
intended for connecting storage subsystems or
devices to hosts.
SFP
Small Form-factor Pluggable. A type of gigabit
interface converter (GBIC) in a compact form
factor. The Fibre Channel ports or 10Gb iSCSI
ports on Nexsan storage devices are SFPs.
SSD
Solid State Disk. A high-performance storage
device that contains no moving parts.
storage area network
An architecture that provides for attachment
of remote computer storage devices to servers
in such a way that the devices appear as loc-
ally attached to the operating system.