G

G_Port

[Fibre Channel] A “Generic” Fabric Port, that can operate as either an E_Port or an F_Port.

A G_Port can determine the operating mode at switch port initialization, F_Port when an N_Port attachment is determined, E_Port when an E_Port attachment is determined.

garbage collection

[Computer System] The process of reclaiming resources that are no longer in use.

Garbage collection has uses in many aspects of computing and storage. For example, in flash storage, background garbage collection can improve write performance by reducing the need to perform whole block erasures prior to a write. See also trim.

gateway

[Network] A device that receives data via one protocol and transmits it via another.

Gb
Gbit

[General] Shorthand for Gigabit.

GB
GByte

[General] Shorthand for Gigabyte.

GB/W

[General] Short for Gigabytes gigabytes per watt.

GB/W is a metric for evaluating the storage capacity provided per unit of power.

GBE

[Network] Shorthand for Gigabit Ethernet.

GBIC

[Fibre Channel] Acronym for Gigabit Interface Converter.

Gbps/W

[General] Short for Gigabits per second per watt.

Gbps/W is a metric for evaluating bandwidth provided per unit of power.

geometry (of a disk)

[Storage System] The mathematical description of the layout of blocks on a disk.

The primary aspects of a disk’s geometry are the number of recording bands and the number of tracks and blocks per track in each, the number of data tracks per cylinder, and the number and layout of spare blocks reserved to compensate for media defects.

Gibit

[General] Shorthand for Gibibit.

GiB
GiByte

[General] Shorthand for Gibibyte.

GiB/W

[General] Short for Gibibytes per watt.

GiB/W measures capacity in units of 230 bytes/watt, while GB/W uses units of 109 bytes/watt.

Gibibit (Gibit)

[General] Shorthand for 1,073,741,824 (230) bits.

Binary notation is most commonly used for semiconductor memory sizes.

See also Gigabit.

Gibibyte (GiB)

[General] Shorthand for 1,073,741,824 (230) bytes.

Binary notation is most commonly used for semiconductor memory sizes.

See also Gigabyte.

Gibps/W

[General] Short for Gibibits per second per watt.

Gibps/W measures bandwidth in units of 230 bits/watt, in contrast to Gbps/W, which measures it in units of 109 bits/watt.

GID

[Management] [Data Security] Abbreviation for "group identifier" (Group IDentifier).

Gigabit (Gb)

[General] Shorthand for 1,000,000,000 (109) bits.

The SNIA uses the base 10 convention commonly found in I/O-related and scientific literature rather than the base 2 convention (1,073,741,824, i.e., 230) common in computer system and software literature.

For Fibre Channel, this refers to a bit transmission rate of 1,062,500,000 bits per second.

See also Gibibit.

Gigabit Ethernet (GBE)

[Network] A group of Ethernet standards in which data is transmitted at 1 Gbit per second, using a 1250 Megabaud line rate and an adaptation of the Fibre Channel Physical Layer 8b/10b encoding.

GBE standards are handled by IEEE 802.3.

Gigabit Interface Converter (GBIC)

[Fibre Channel] A transceiver that converts between electrical signals internal to a Fibre Channel or Ethernet device and the external optical or electrical interface of that device.

These devices are obsolete and have been replaced by smaller, cheaper, and faster devices, including SFP, SFP+, XFP and related XAUI-based modules.

Gigabyte (GB)

[General] Shorthand for 1,000,000,000 (109) bytes.

The SNIA uses the base 10 convention commonly found in I/O-related and scientific literature rather than the base 2 convention (1,073,741,824, i.e., 230) common in computer system and software literature.

See also Gibibyte.

Gigabyte System Network (GSN)

1. [Network] A common name for the HIPPI-6400 standard for 800 MByte per second links.

2. [Network] A network of devices that implement the HIPPI-6400 standard.

GL_Port

[Fibre Channel] A “Generic Loop” Port, able to operate as an E_Port, F_Port or FL_Port.

A GL_Port can determine operating mode at switch port initialization, FL_Port when an NL_Port attachment is determined, F_Port when an N_Port attachment is determined, E_Port when an E_Port attachment is determined.

GLM

[Fibre Channel] Acronym for Gigabaud Link Module.

Graphical User Interface (GUI)

[Computer System] A form of user interface to intelligent devices characterized by pictorial displays and highly structured, forms oriented input.

A GUI is valued for perceived ease of use compared with a command line interface.

Green Storage Initiative (GSI)

[Standards] [Energy] An initiative within the SNIA with a special interest in marketing, education, promotion and development of green storage technologies and support for the technical work of the Green Storage TWG.

greenwashing

[Energy] A result of excessive marketing and ineffective engineering.

In fond memory of Tom Clark, who penned this definition ca. 2008.

Group Identifier (GID)

[Data Security] A collection of computer user identifiers and possibly other group identifiers used as a convenience in assigning resource access rights or operational privileges.

groupid

[Data Security] Shorthand for group identifier.

GSI

[Standards] Acronym for the SNIA Green Storage Initiative.

GSN

[Network] Acronym for Gigabyte System Network.

GUI

[Computer System] Acronym for Graphical User Interface.