SNIA Online Dictionary

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I/O	[Computer System] Abbreviation for input/output.
I/O adapter	[Computer System] An adapter that converts between the timing and protocol requirements of a system's memory bus and those of an I/O interconnect or network. In the context of storage subsystems, I/O adapters are contrasted with embedded storage controllers, that not only adapt between buses and interconnects, but also perform transformations such as device fan-out, data caching, and RAID. Host bus adapters (HBAs) and Ethernet NICs are types of I/O adapters.
I/O bottleneck	[Computer System] Any resource in the I/O path that limits data transfer capacity of a system. Examples of resources that may limit the data transfer capacity of a system include a device driver, host bus adapter, I/O interconnect, intelligent controller, and disk.
I/O bus	[Computer System] Synonym for I/O interconnect.
I/O driver	[Computer System] A host computer software component (usually part of an operating system) whose function is to control the operation of peripheral controllers or adapters attached to the host computer. I/O drivers manage communication and data transfer between applications and I/O devices.
I/O intensity	[Computer System] A characterization of an application that describes how strongly performance depends on the performance of the I/O subsystem that provides I/O services to the application. I/O intensive applications may be either data transfer intensive or I/O request intensive or both.
I/O interconnect	[Computer System] Any path used to transfer data and control information between components of an I/O subsystem. An I/O interconnect consists of cables, connectors, and all associated transmitters, receivers, and other required components. I/O interconnects are typically optimized for the transfer of data. See channel, device channel, network.
I/O load	[Computer System] A metric of I/O requests made to an I/O subsystem over a period of time.
I/O load balancing	[Computer System] Load balancing of I/O.
I/O operation	[Computer System] A read, write, or control function performed to, from or within a computer system. See I/O request.
I/O power efficiency	[Storage System] 1. The ratio of maximum IOPS deliverable by a system, to the input power required to deliver those IOPS. 2. The ratio of data transfer rate readable or writable by a system, to the input power required to achieve that data transfer rate.
I/O request	[Computer System] A request by an application to read or write a specified amount of data. In the context of real and virtual disks, I/O requests specify the transfer of a number of blocks of data. See I/O operation.
I/O subsystem	[Computer System] A set of devices and software components that operate together to provide data services. A storage subsystem is one type of I/O subsystem.
I2C	[Network] The first generation of a hardware bus typically used to connect management related devices to a system. See System Management Bus.
I3C	[Hardware] The second generation of a hardware bus typically used to connect management related devices to a system.
IaaS	[Services] Acronym for Infrastructure as a Service.
ICMP	[Network] Acronym for Internet Control Message Protocol.
IDE	[Storage System] Acronym for Integrated Drive Electronics.
idempotence	[General] A property of an operation in which the same result is obtained no matter how many times the operation is repeated.
idempotent	[Computer System] A property of an operation in which a single effect occurs no matter how many times the operation is invoked.
identification	[Data Security] The process of determining the unique identity of an entity.
identity	[Data Security] Representation of an actual user (or application or service or device). An example is the assignment of the user name joej (the identity) to represent the human user Joe Jones for purposes of authentication and authorization.
idle	[Storage System] A state in which a storage system is serving no user-initiated I/O requests, but is ready to service them upon arrival with normal latency. Storage systems may perform extensive system-initiated I/O during idle periods as they execute routine background housekeeping tasks.
idle power	[Energy] The power consumption of a system that is idle.
Idle word	[Network] In a data stream using 8B/10B encoding, an ordered set of four transmission characters normally transmitted between frames to indicate that no data is being transmitted.
IDS	[Data Security] Acronym for Intrusion Detection System.
IETF	[Network], [Standards] Acronym for Internet Engineering Task Force.
iFCP	[Network], [Fibre Channel] A gateway-to-gateway protocol that provides Fibre Channel Fabric services to Fibre Channel devices over a TCP/IP network.
ignored	A field that is not interpreted by its receiver.
IKE	[Network], [Data Security] Acronym for Internet Key Exchange.
ILM	[Data Management] Acronym for Information Lifecycle Management.
IMA	[iSCSI] Acronym for iSCSI Management API.
implicit addressing	[Storage System] A form of addressing, usually used with tapes, in which the data's address is inferred from the form of the access request. Tape commands that do not include an explicit block address but implicitly specify the next or previous block from the current tape position, from which the block address must be inferred by the device. See explicit addressing.
import/export element	[SCSI] Synonym for entry/exit slot.
in-band	[Network] Transmission of a separate data stream, such as management information, over the same medium as the primary data stream. See out-of-band.
in-band data deduplication	[Storage System] Deprecated synonym for inline data deduplication.
incident	[Data Security] An occurrence that actually or potentially jeopardizes the confidentiality, integrity, or availability of an information system or the information the system processes, stores, or transmits or that constitutes a violation or imminent threat of violation of security policies, security procedures, or acceptable use policies. [NIST FIPS 200]
incineration	[Data Security] A method of sanitization that reduces a storage device or element to ash, in an approved facility. [ISO/IEC 27040]
INCITS	[SCSI], [Standards] The INCITS SCSI Storage Interfaces Technical Committee. The INCITS T10 Technical Committee is the standards development committee accredited by INCITS to develop SCSI standards for communication between host devices (initiators) and external controllers (targets).
INCITS Fibre Channel (T11) Technical Committee	[Fibre Channel], [Standards] The standards development committee accredited by INCITS to develop standards related to Fibre Channel.
INCITS T10	[SCSI], [Standards] The INCITS SCSI Storage Interfaces Technical Committee (INCITS TC T10). The INCITS T10 Technical Committee is the standards development committee accredited by INCITS to develop SCSI standards for communication between from host devices (initiators) to storage device controllers (targets).
INCITS T13	[Standards] The INCITS ATA Storage Interfaces Technical Committee. The INCITS T13 Technical Committee is the standards development committee accredited by INCITS to develop ATA standards for communication between a host and a storage device.
incremental backup	[Data Recovery] A backup of data objects modified since a previous backup. Incremental backup is a collective term for cumulative incremental backups and differential incremental backups. See full backup.
independent access array	[Storage System] A disk array whose data mapping is such that different member disks can execute multiple application I/O requests concurrently. See parallel access array.
InfiniBand	[Computer System] An industry standard, channel-based, switched fabric interconnect architecture for server and storage connectivity The committee standardizing InfiniBand™ is the InfiniBand® Trade Association.
information	[Data Management] Data that is interpreted within a context such as an application or a process.
information assurance	[Data Security] Measures that protect and defend information and information systems by ensuring their availability, integrity, authentication, confidentiality, and nonrepudiation. Information assurance encompasses system reliability and strategic risk management, and includes providing for restoration of information systems using protection, detection, and reaction capabilities.
Information Lifecycle Management	[Data Management] The policies, processes, practices, services and tools used to align the business value of information with the most appropriate infrastructure from the time information is created through its final disposition. Information is aligned with business requirements through management policies and service levels associated with applications, metadata and data.
information management	[Data Management] The discipline and function of oversight and control of information resources.
information management services	[Data Management] The processes associated with managing information as it progresses through various lifecycle states associated with a business process. These services exploit information about data content and relationships in making decisions. Examples include records management and content management applications.
information model	[Data Management] A repository-independent definition of entities (objects) and the relationships and interactions between these entities. The CIM schemas are an example of an information model. An information model differs from a data model, which is repository-specific.
information resource domain	[Management] The category of resources that exclusively encompass information services.
information security	[Data Security] Preservation of confidentiality, integrity and availability of information. [ISO/IEC 27000:2018] In addition, other properties such as authenticity, accountability, non-repudiation and reliability can also be involved.
information service	[Management] A set of functions that treat data within an interpretation context.
information system	[Data Security] The entire infrastructure, organization, personnel and components for the collection, processing, storage, transmission, display, dissemination and disposition of information.
Information Technology	[General] All aspects of digital information creation, access, use, storage, transport and management. The term Information Technology addresses all aspects of computer and storage systems, networks, users and software in an enterprise.
Information Unit	[iSCSI], [Fibre Channel] 1. [iSCSI] A delimited and sequenced set of information in a format appropriate for transport by the service delivery subsystem. An iSCSI Information Unit may contain a command, data, response, or task management request. [Fibre Channel] A related collection of data specified by an FC-4 to be transferred as a single FC-2 Sequence.
Infrastructure as a Service	[Services] Delivery over a network of an appropriately configured virtual computing environment, based on a request for a given service level. Typically, Infrastructure as a Service (IaaS) is either self-provisioned or provisionless and is billed based on consumption.
infrastructure-based virtualization	[Computer System] Virtualization implemented in the storage fabric, in separate devices designed for the purpose, or in network devices. Examples are separate devices or additional functions in existing devices that aggregate multiple individual file system appliances or block storage subsystems into one such virtual service, functions providing transparent block or file system mirroring functions, or functions that provide new security or management services.
ingress Routing Function role	[Fibre Channel] A process within a Routing Function that forwards the frame to the next hop Routing Function or Egress Routing Function.
initial relative offset	[Network] The relative offset of the block or sub-block transmitted by the first frame in a sequence, specified by an upper layer protocol. The initial relative offset need not be zero.
initialization	[Computer System] The startup and initial configuration of a system or component.
initiator	[SCSI], [Computer System] 1. [Computer System] The system component that originates an I/O command over an I/O interconnect. 2. [SCSI] The endpoint that originates a SCSI I/O command sequence. I/O adapters, network interface cards, and intelligent I/O interconnect control ASICs are typical initiators. See LUN, originator, target, target port identifier.
initiator NVMe_Port	[Fibre Channel] NVMe_Port that is the NVMe host port for an FC_NVMe association.
initiator port identifier	[SCSI] The interconnect address of an initiator.
Initiator Session Identifier	[iSCSI] The unique identifier that an initiator assigns to its end point of the session. When combined with the iSCSI Initiator Name, the Initiator Session Identifier provides a worldwide unique name for its SCSI Initiator Port.
inline data deduplication	[Storage System] Data deduplication performed before writing the deduplicated data. See post-process data deduplication
inode	[File System] A persistent data structure in a UNIX or UNIX-like file system that describes the location of some or all of the disk blocks allocated to a file.
input/output	The process of moving data between a computer system's main memory and an external device or interface. Input/output (I/O) encompasses reading, or moving data into a computer system's memory from another location, and writing, or moving data from a computer system's memory to another location. Example locations include storage device, display, printer, or network connected to another computer system.
instantiation	[General] The creation of an instance of a class or object oriented abstraction.
Integrated Drive Electronics	[Computer System] A type of hardware interface formerly used to connect hard disks, CD-ROMs and tape drives to a PC. The IDE interface is defined by the ATA specification.
integrity	[Data Security] Property of accuracy and completeness. [ISO/IEC 27000:2018]
intelligent controller	[Computer System] A device for handling requests that includes a processor or sequencer programmed to autonomously process a substantial portion of requests. A storage controller is an example of an intelligent controller.
intelligent device	[Computer System] A computer, storage controller, storage device, or appliance.
Intelligent Platform Management Interface	[Management] A protocol used to perform management and monitoring operations on a system independent of the host system components.
Inter-Fabric	The entire interconnection of Fabrics and Inter-Fabric Routers.
Inter-Fabric Router	[Fibre Channel] A device that performs Inter-Fabric Routing and consists of a Routing Function, Translate Domain Switches, and Front Domain Switches.
Inter-Fabric Routing	The process of forwarding frames through a specific Routing Function, including the translation of N_Port_IDs.
Inter-Switch Link	[Fibre Channel] A Fibre Channel link connecting one switch to another switch. See FC-SW.
interconnect	[Computer System] A physical means by which system elements and devices are connected together and through which they can communicate with each other. I/O buses and networks are examples of interconnects.
interface connector	[Network] An optical or electrical connector that connects the media to the transmitter or receiver. An interface connector consists of a receptacle and a plug.
Intermediate Routing Function	A process within a Routing Function that validates the frame headers, updates the IFR-Header, removes and adds a new Enc_Header, then forwards the frame to the next hop Routing Function.
intermix	A Fibre Channel class of service that provides a full data transfer capacity dedicated Class 1 connection, but allows connectionless Class 2 and Class 3 traffic to share the link during intervals when data transfer capacity is unused.
International Organization for Standardization	[Standards] A worldwide federation of national standards bodies. A non-governmental organization, covering more than 145 countries, whose work results in international agreements that are published as International Standards and other types of ISO documents.
Internet Control Message Protocol	[Network] A control protocol, strongly related to IP and TCP, used to convey a variety of control and error messages.
Internet Engineering Task Force	[Network], [Data Security], [Standards] The community concerned with evolution and operation of the Internet. The IETF is the standards body responsible for Internet standards called RFCs, including SNMP, TCP/IP and policy for QoS. The IETF has a web site at www.ietf.org.
Internet Key Exchange	[Network], [Data Security] A protocol specified by the IETF that performs mutual authentication between two parties and establishes an IKE Security Association (SA) that includes shared secret information that can be used to efficiently establish SAs for Encapsulating Security Payload (ESP) or Authentication Header (AH) and a set of cryptographic algorithms to be used by the SAs to protect the traffic that they carry. IKEv2 is defined in RFC-4306. IKE Version 2 (IKEv2) is not compatible with Version 1.
Internet Protocol	[Network] A standard protocol that provides connectionless, best effort delivery of datagrams across heterogeneous physical networks. See TCP, UDP.
Internet Small Computer Systems Interface	[Storage System] A transport protocol that provides for the SCSI protocol to be carried over a TCP based IP network, standardized by the Internet Engineering Task Force and described in RFCs 791, 1122, 2003, and 3720.
Internet Storage Name Service	[iSCSI] A protocol and mechanism for intelligent discovery of storage devices in an IP network.
interoperability	[Computer System] The ability of systems to work with or use data and protocols from other systems.
interrupt	[Computer System] A hardware or software signal that causes a computer to stop executing its instruction stream and switch to another stream. Software interrupts are triggered by application or other programs. Hardware interrupts are caused by external events, to notify software so it can deal with the events.
intrusion	[Data Security] Unauthorized access to a network or a network-connected system, that is, deliberate or accidental unauthorized access to information systems, to include malicious activity against information systems, or unauthorized use of resources within information systems. [ISO/IEC 27039:2015]
intrusion detection	[Data Security] The process of identifying that an intrusion has been attempted, is occurring, or has occurred.
Intrusion Detection System	[Data Security] Technical system that is used to identify that an intrusion has been attempted, is occurring, or has occurred and possibly respond to intrusions in information systems and networks. [ISO/IEC 27039:2015]
IOPS / IOPs / iops	[Storage System] Shorthand for I/O Operations per second. IOPs can also be the plural of IOP (short for I/O operation), depending on context.
IOPS/W	[Energy] Input/Output operations per second per watt. IOPS/W is a metric for evaluating storage I/O performance per unit of power.
IP	[Network] Acronym for Internet Protocol.
IP Security	[Network], [Data Security] A suite of cryptographic algorithms, protocols and procedures used to protect information, authenticate communications, control access, and provide non-repudiation at the IP layer. The two key protocols in IPsec are the Authentication Header (AH) and Encapsulating Security Payload (ESP) protocols.
IPMI	[Hardware] Acronym for Intelligent Platform Management Interface.
IPsec	[Network], [Data Security] Shorthand for IP security.
iSCSI	[Storage System] Acronym for internet Small Computer Systems Interface.
iSCSI Device	[iSCSI] A SCSI device using an iSCSI service delivery subsystem, in other words an iSCSI-specific transport mechanism for SCSI commands and responses. See IETF RFC 3720.
iSCSI initiator Name	[iSCSI] The worldwide unique name of an iSCSI initiator.
iSCSI Initiator Node	[iSCSI] The initiator in an iSCSI Device.
iSCSI initiator port	[iSCSI] A SCSI initiator port used for iSCSI.
iSCSI layer	[iSCSI] The layer that builds/receives iSCSI Protocol Data Units and relays/receives them to/from one or more TCP connections that form an iSCSI session.
iSCSI Management API	[iSCSI] SNIA standard for a C language based API for managing iSCSI capable HBAs and NICs, along with the device drivers that control them.
iSCSI name	[iSCSI] The name of an iSCSI initiator or iSCSI target.
iSCSI Network Entity	[iSCSI] A device or gateway that is accessible from a TCP/IP network and has one or more iSCSI Network Portals.
iSCSI Network Portal	[iSCSI] A component of an iSCSI Network Entity that has a TCP/IP address and can be used by a node within that component for connections to another iSCSI Node. An Initiator iSCSI Network Portal is identified by its IP address. A target iSCSI Network Portal is identified by its IP address and listening TCP port.
iSCSI Node	[iSCSI] A single iSCSI Initiator Node or iSCSI Target Node.
iSCSI Portal Group	[iSCSI] A set of iSCSI Network Portals within an iSCSI Node. When a session has multiple connections, all connections in a session must use the portals in a single iSCSI Portal Group.
iSCSI Portal Group Tag	[iSCSI] A tag identifying all portals in an iSCSI Portal Group.
iSCSI SAN	[iSCSI] Block-level Storage Area Network over TCP/IP using the iSCSI protocol.
iSCSI Session	[iSCSI] The top level relationship between a specific iSCSI Initiator Node and iSCSI Target Node, equivalent to the I_T nexus. A session contains one or more connections.
iSCSI Session Identifier	[iSCSI] A unique identifier for a session between an iSCSI Initiator Node and iSCSI Target Node.
iSCSI Target Name	[iSCSI] The worldwide unique name of an iSCSI Target Node.
iSCSI Target Node	[iSCSI] The target in an iSCSI Device.
iSCSI Target Port	[iSCSI] A SCSI target port used for iSCSI.
iSER	[Storage System] iSCSI Extensions for RDMA. See IETF RFC 7145.
ISID	[iSCSI] Acronym for Initiator Session Identifier.
ISL	[Fibre Channel] Abbreviation for Inter-Switch Link.
iSNS	[iSCSI] Acronym for Internet Storage Name Service.
iSNS Discovery Domain	[iSCSI] Grouping of storage nodes for facilitating discovery and login control of these nodes.
ISO	[Standards] Acronym for International Organization for Standardization.
IT	[General] Acronym for Information Technology.
IT security	[Data Security] All aspects related to defining, achieving, and maintaining confidentiality, integrity, availability, non-repudiation, accountability, authenticity, and reliability of information assets.
IU	[General] Acronym for Information Unit.
iWARP	[Network], [Storage System] The Internet Wide Area Remote Direct Memory Access Protocol. See IETF RFC 7306.
I_T nexus	[SCSI] A relationship specified in SAM between a SCSI initiator port and a SCSI target port.