ATTO Technology VT-Class manual Appendix

Term	Definition
F_port	A port in the FC fabric where a N_port may attach
FC-AL	Fibre Channel Arbitrated Loop: an FC network in which up to 126 systems and devices are
	connected in a loop topology, with each transmitter connecting to the receiver of the device
	to its logical right; multiple FC-AL loops can be connected via a fabric switch
FL-port	A port in the FC fabric where a NL_port may attach in an arbitrated loop
firmware	Software stored in read-only memory (ROM) or programmable ROM; easier to change than
	hardware but more difficult to change than software stored on disk; firmware is responsible
	for the behavior of the system when it is first switched on
GBIC	A removable serial transceiver module which provides a connection between an external
	FC interface and a host interface board
host	a processor which communicates with devices over an interface
hot swapping	Components are removed and replaced while the unit is running, with power to either the
	component or a device connected to the unit
initiator device	A component which originates a command
JBOD	Just a Bunch of Disks: a storage subsystem of multiple independent disk drives
L_port	a port in an arbitrated loop, either a NL_port or a FL_port
LED	Light-emitting diode, a type of diode that emits light when current passes through it; visible
	LEDs are used as indicator lights on the Diamond-VT
LUN	Logical Unit Number: a SCSI or FC identifier of a device. A LUN is associated with a RAID
	group or Virtual Drive.
N_port	a port attached to a node used with point to point or fabric configurations
NL_ port	a port attached to a node in FC arbitrated loop or fabric loop
originator	an initiating device; a component which originates a command
partition	a continuous range of addresses in a storage subsystem that appear as a logical unit; used
	to subdivide and manage a storage subsystem
port	an access point in a device: see N_port, NL_port, etc.
receiver	the ultimate destination of data transmission; a terminal device
RAID	originally Redundant Array of Inexpensive Disks, now Redundant Array of Independent
	Drives: a storage system spanning multiple disk drives.
	The following standard RAID specifications will be used here:
	RAID 0: non-redundant striped array; drives are accessed alternately, as if stacked one on
	top of the other; no data protection
	RAID 1: mirrored arrays: information written to one disk is also written to another
	simultaneously; provides complete data protection
	RAID 10: striping of mirrored groups
	RAID 5: striping across multiple disks offering redundancy by including a parity block in
	every stripe; the parity block is used to reconstruct the data if a single drive in the
	subsystem fails
SFP	Small Formfactor Pluggable: a removable transceiver which provides the connection
	between an external FC interface and a host interface
subpartition	a convenient term used to describe the allocation nature of a partition; a partition may be
	split into a number of subpartitions (each a partition in its own right) and a collection of
	contiguous subpartitions may be merged into a partition
topology	logical layout of the parts of a computer system or network and their interconnections
Virtual Drive	the presentation of a collection of disk drives as a single logical disk, also known as a RAID group.
Virtual Drive ID	a unique identifier associated with each Virtual Drive and displayed via CLI

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Appendix