Installation manual

xvii ATTO Technology Inc. ATTO Utilities Installation and Operation Manual
L_port A port in an arbitrated loop, either a NL_port or a FL_port.
LED Light-Emitting Diode: a type of diode which emits light when current passes through it.
Visible LEDs are used as indicator lights on all sorts of electronic devices.
LUN Logical Unit Number: an identifier for a logical unit (0-7).
multi-mode fiber An optical fiber which can carry several beams of light at once.
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 Fibre Channel arbitrated loop or fabric loop configuration.
originator An initiating device; a component which originates a command.
parity checking A method which verifies the accuracy of data transmitted over the SCSI bus by adding
one bit in the transfer to make the sum of all the bits either odd or even (for odd or even
parity). An error message occurs if the sum is not correct.
PCI Peripheral Component Interconnect. allows peripherals to be connected directly to
computer memory, bypassing the slower ISA and EISA busses.
Point-to-Point A topology where two ports communicate.
port An access point in a device: see N_port, NL_port, etc.
port address
read direct
The address, assigned by the PCI bus, through which commands are sent to the
storage controller. Also known as “port number”.
A RAID Group feature in which data is passed directly to the OS without first being read
into the storage controller cache. This can result in read performance improvements,
especially for large, sequential transfers. This feature is only available for RAID 5.
receiver The ultimate destination of data transmission; a terminal device.
SCSI Small Computer Systems Interface: a processor-independent standard for system-level
interface between a computer and intelligent devices including hard disks, floppy disks,
CD-ROM, printers, scanners, etc.
SES SCSI Enclosure Services: a processor which identifies
individual drives, all the drives in
the same enclosure, all the drives in a single RAID group and faulted drives; selects drives,
and monitors the status of the enclosure.
single-mode fiber An optical fiber with a small core which supports one wavelength (ray of light). The core
radius is nearly equal to the wavelength of the source.
topology The logical layout of the parts of a computer system or network and their
interconnections.
transceiver A transmitter/receiver module.
transfer rate The rate at which bytes or bits are transferred, as in megabytes or gigabits per second.
Term Definition