Scsi addressing, Scsi bus, Scsi device – Dell PowerVault 35F (Fibre Channel Bridge) User Manual

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Glossary: Dell PowerVault 35F User's Guide

file:///C|/Users/rishi_sood/Desktop/35F/ug/glossary.htm[3/21/2013 11:16:26 AM]

SCSI Addressing

A fast/wide SCSI adapter supports up to 16 devices, including itself. Each device has its own unique SCSI
address. The SCSI address of a device dictates the device’s priority when arbitrating for the SCSI bus.
SCSI address "7" has the highest priority. The next highest priority address is "6" followed by 5, 4, 3, 2, 1,
0, 15, 14, 13, 12, 11, 10, 9, 8, with "8" being the lowest priority address.

The fast/wide SCSI adapter is factory set to address 7. A narrow SCSI adapter supports up to eight
devices, including itself. SCSI address "7" has the highest priority followed by 6, 5, 4, 3, 2, 1, and 0.

SCSI Bus

The means of transferring SCSI data between SCSI devices. It is an 8-bit or 16-bit bus that supports up to
eight or sixteen devices (including itself), in any mix of initiators and targets, with the limitation that at
least one initiator and one target must be present.

SCSI Device

A single unit on the SCSI bus, identifiable by a unique SCSI address. A SCSI device can act as an initiator
or target. For SCSI-3, each SCSI device supports up to sixteen LUNs.

SCSI Port

An opening at the back of the PowerVault 35F providing connection between the SCSI adapter and the
SCSI bus.

SCSI Status

A menu name used to show the number of SCSI devices on the bus.

Shortwave

Lasers or LEDs that emit light with wavelengths around 780 nm or 850 nm. When using multimode fibre
(50 nm), shortwave lasers can be used with FC links less than 500m. To achieve longer lengths, single-
mode fibre is required. The preferred fibre core size is 50 micron as this fibre has large bandwidth so that
the distance is limited by the fibre attenuation. A 62.5 micron core size is also supported for compatibility
with existing FDDI installations. Fibre of this type has smaller bandwidth and, in this case, the distance is
limited by the fibre bandwidth.

SNMP

Simple Network Management Protocol.

Speed

A status type in the FC Status Menu showing the speed (1063 Mbps) of the FC adapter.

Target

A SCSI device (usually the peripheral) that responds to an operation requested by a SCSI initiator (usually
the host system). SCSI peripherals are targets, but for some commands (for example, a COPY command),
the peripheral may need to act temporarily as an initiator.

Terminator Block/Termination

An electrical connection at each end of the SCSI bus composed of a set of resistors (or possibly other

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