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Online SNIA Dictionary
[Services]
Acronym for Software as a Service.
[SCSI]
Acronym for SCSI Architecture Model.
The SCSI Architecture Model is developed and owned by the T10 working group of ANSI. SAM has undergone numerous revisions, each being consecutively named as SAM-2, SAM-3 and so on, the latest revision being SAM-5.
[iSCSI] [Network] [Computer System]
This is the normal meaning in SNIA documents.
2. Acronym for Server Area Network, which connects one or more servers.
3. Acronym for System Area Network, an interconnected set of system elements.
[Data Security]
A process or method to sanitize.
[ISO/IEC 27040]
[Data Security]
Render access to target data on storage media infeasible for a given level of effort. [ISO/IEC 27040]
Clear, purge, and destruct are actions that can be taken to sanitize storage media. See media sanitization.
[SCSI]
Acronym for Serial Attached SCSI.
[SCSI]
Short for Serial Attached SCSI Expander.
[Storage System]
Acronym for Serial Advanced Technology Attachment.
[Storage System]
A disk whose instantaneous I/O load is as great as or greater than its capability to satisfy the requests comprising the load.
Mathematically, a saturated disk's I/O queue eventually becomes indefinitely long. In practice, however, user reaction or other system factors generally reduce the rate of new request arrivals for a saturated disk.
[Computer System]
To grow or support growth in such a way that all capabilities of the system remain in constant ratio to each other.
A storage subsystem whose data transfer capacity increases by the addition of buses as its storage capacity increases by the addition of disks is said to scale.
[Management] [Data Management]
1. A collection of information models or data models.
2. Data that describes the organization and format of other data.
[Data Communication]
Modifying data by XORing each bit with a pattern generated by a linear feedback shift register to minimize repetitive character patterns.
[Storage System] [Computer System]
1. A parameterized list of primitive I/O interconnect operations intended to be executed in sequence.
Often used with respect to ports, most of which are able to execute scripts of I/O commands autonomously (without policy processor assistance).
2. A sequence of instructions intended to be parsed and carried out by a command line interpreter or other scripting language.
Perl, VBScript, JavaScript and Tcl are all scripting languages. See Command Line Interface.
[Storage System]
A background function that reads user data and check data blocks in a storage device and relocates them if media defects or errors are found.
[SCSI]
Acronym for Small Computer System Interface.
[SCSI]
An adapter that connects an intelligent device to a SCSI interconnect.
See HBA, host bus adapter.
[SCSI]
The full address used by a computer to communicate with a SCSI device, including an adapter number (required with computers configured with multiple SCSI adapters), and the target ID of the device.
SCSI addresses do not include logical unit number, because those are not used for communication.
[SCSI]
Deprecated synonym for SCSI interconnect.
[SCSI]
A standard for management of environmental factors such as temperature, power, voltage, etc.
[SCSI]
A standard for media changer devices (i.e., libraries).
[SCSI]
A protocol to transport SCSI operations over PCI Express.
[SCSI]
The SCSI term for an entity in a SCSI Device that provides the SCSI functionality to interface with a service delivery subsystem or transport.
[SCSI]
A standard for sequential-access devices (i.e., tape drives).
[General]
A trade association incorporated in 1996 to promote all forms of SCSI technology in the market.
[Management]
Acronym for Software Defined Data Center.
[Network]
Acronym for Synchronous Digital Hierarchy.
[Storage System]
Shorthand for software-defined storage.
[Data Security]
A key used in a symmetric cryptosystem to both encrypt and decrypt data.
The key must remain confidential to the using parties to ensure the security of the cryptosystem.
[Storage System]
The unit in which data is physically stored and protected against errors on a fixed block architecture disk.
A sector typically consists of a synchronization pattern, a header field containing the block's address, data, a checksum or error correcting code, and a trailer. Adjacent sectors are often separated by information used to assist in track centering. Most often, each sector holds a block of data. See disk block.
[Data Security]
An algorithm that generates a fixed-size digest from its input (e.g., a message).
The algorithm has the properties that different inputs are extraordinarily unlikely to yield the same digest, small changes in its input lead to large changes in its output, and it is computationally intractable to generate an input that yields the same digest as another given input.
A type of multi-tenancy that employs security controls to explicitly guard against data breaches and provides validation of these controls for proper governance. [ISO/IEC 27040]
Secure multi-tenancy exists when the risk profile of an individual tenant is no greater than it would be in a dedicated, single-tenant environment. In very secure environments even the identity of the tenants is kept secret. See multi-tenancy.
[Data Security]
A suite of cryptographic algorithms, protocols and procedures used to provide security for communications used to access the world wide web.
The characters "https:" at the front of a URL cause SSL to be used to enhance communications security. More recent versions of SSL are known as TLS (Transport Level Security) and are standardized by the Internet Engineering Task Force (IETF).
SSL is a predecessor of TLS and is considered a vulnerability if it is supported in a product.
See also SSL.
[Data Security]
A set of elements, a security policy, a security authority, and a set of security-relevant activities in which the set of elements are subject to the security policy for the specified activities, and the security policy is administered by the security authority for the security domain. [ISO/IEC 10181-1:1996].
[Data Security]
A single or a series of unwanted or unexpected events that have a significant probability of compromising business operations and threatening information security.
[Data Security]
The protective measures and controls that are prescribed to meet the security requirements specified for a system.
Safeguards may include but are not necessarily limited to: hardware and software security features, operating procedures, accountability procedures, access and distribution controls, management constraints, personnel security, and physical structures, areas, and devices. Also called safeguards (without the adjective).
[Data Security]
A measure of the difficulty of subverting the cryptographic protection (e.g. discovering the key) using classical computers.
Security strength is specified in bits and is a specific value from the set {80, 112, 128, 192, 256}. A security strength of b bits means that of the order of 2b operations are required to break the system.
[Data Security]
A set of security functional and assurance requirements and specifications to be used as the basis for evaluation of an identified product or system, most commonly associated with ISO 15408.
[Storage System]
A type of self encrypting storage device.
[Storage System]
A storage device that has the native ability to encrypt all user data written to and decrypt the same data read from it, and that prevents access until a credential is supplied.
Tape drives, disk drives and other types of storage devices may all be designed to be self encrypting storage devices.
[Long-Term Retention]
A self-describing container format, developed by the SNIA, appropriate for the long-term storage of digital information.
[Data Security]
A public key certificate whose digital signature may be verified by the public key contained within the certificate.
The signature on a self-signed certificate protects the integrity of the data, but does not guarantee authenticity of the information. The trust of self-signed certificates is based on the secure procedures used to distribute them. [NIST SP 800-57 Part 1]
[Data Security]
Information that, as determined by a competent authority, must be protected because its disclosure, modification, destruction, or loss will cause perceivable damage to someone or something [ISO/IEC 2382:2015].
A set of Fibre Channel data frames with a common Sequence-ID (SEQ-ID), corresponding to one message element, block, or Information Unit.
Sequences are transmitted from the sequence initiator to the sequence recipient.
A Fibre Channel signaling feature that designates which end of an exchange has authority to send the next sequence.
An Nx-Port that initiates a sequence and transmits data frames to a destination Nx_Port.
An N-Port or NL-Port that receives Data frames from a Sequence Initiator and, if applicable, transmits responses (Link Control frames) to the Sequence Initiator.
A data structure that tracks the state of a sequence.
Both Sequence Initiators and Sequence Recipients have Sequence Status Blocks for each active sequence.
[Storage System]
An I/O load consisting of consecutively issued read or write requests to adjacently addressed data.
Sequential I/O is characteristic of data transfer intensive applications. See random I/O.
A number transmitted with each data frame in a sequence that identifies the frame as part of the sequence.
[Computer System]
Short for Serializer Deserializer.
[General]
The transmission of data bits one at a time over a single link.
[Computer System]
An adapter that connects an intelligent device to an RS232 or RS425 serial communications link.
Serial adapters are sometimes used by storage subsystems, filers, and other intelligent devices to connect to serial consoles for management purposes. See host adapter.
[Storage System]
A version of the ATA interface that uses a serial connection architecture.
[SCSI]
A switching device that uses virtualization to allow multiple SAS devices to be connected to each initiator port.
[Computer System]
A real or emulated communication terminal used by humans to manage an intelligent device.
Serial consoles connect to the devices' virtual or physical serial adapters.
[Computer System]
1. An intelligent device, usually a computer, that provides services to other intelligent devices, usually other computers or appliances. See client.
2. An asymmetric relationship with a second party (a client) in which the client initiates requests and the server responds to those requests.
[Computer System]
Synonym for host based virtualization.
[Network]
A network file system access protocol designed primarily used by Windows clients to communicate file access requests to Windows servers.
Current versions of the SMB protocol are referred to as CIFS, the Common Internet File System.
[General]
An agreement between a service provider, such as an IT department, an internet services provider, or an intelligent device acting as a server, and a service consumer.
A service level agreement defines parameters for measuring the service, and states quantitative values for those parameters.
[General]
A partition of an SLA consisting of individual metrics and operational information to enforce and/or monitor the SLA.
Service Level Objectives may be defined as part of an SLA, an SLS, or in a separate document. Each is a set of parameters and their values. The actions of enforcing and reporting monitored compliance can be implemented as one or more policies. See Service Level Agreement.
[Management]
An IETF standards track protocol that provides a framework to allow networking applications to dynamically discover the existence, location, and configuration of networked services in enterprise networks.
[Management]
A particular resource that is directly accessed via the Redfish service entry point.
This resource serves as a starting point for locating and accessing the other resources and associated metadata that together make up an instance of a Redfish service.
[SCSI] [Standards]
1. Acronym for SCSI Enclosure Services.
2. Acronym for Solution Exchange Standard.
[Hardware] [Standards]
[Standards] The SNIA SFF Technology Affiliate Technical Work Group.
[Hardware] Acronym for Small Form Factor.
[Hardware]
Acronym for Small Form Factor Pluggable
Abbreviation for Source Fabric_Identifier.
[File System]
A resource such as a data volume or a printer device made available for use by users on other computer systems.
For example, a printer or a collection of files stored in a single directory tree on a file server may be made available as a share. CIFS clients, which include most networked personal computers, typically map a share to a drive letter.
[Data Security]
A pre-shared key that has been distributed to communicating parties prior to beginning of an encrypted communication.
[Storage System]
A modular enclosure for storage devices such as disks, tapes, and canisters. Storage shelves usually contain power supplies and cooling devices, and have pre-wired backplanes that carry power and I/O interconnect signals to storage devices.
[Data Security]
A room or container designed to attenuate electromagnetic radiation.
[Storage System]
A recording technique for storing data on an HDD where data is recorded on overlapping tracks which must be written sequentially.
[General] [SCSI]
1. Acronym for Semiconductor Industries Association.
2. Acronym for SCSI Industry Association.
[Network] [Standards]
An IETF protocol for monitoring and managing systems and devices in a network.
The data being monitored and managed is defined by a MIB. The functions supported by the protocol are the request and retrieval of data, the setting or writing of data, and traps that signal the occurrence of events.
[General]
A configuration in which the referenced component is not redundant.
See redundant (component).
[SCSI]
An electrical signaling technique in which all control and data signals are represented by a voltage difference from a common ground.
See differential.
[Storage System]
A form of data deduplication that operates at a granularity of an entire file or data object.
[Network]
A fiber optic cabling specification that provides for up to 10 kilometer distance between devices.
Optical fiber that is designed for the transmission of a single ray or mode of light as a carrier.
Single mode fibre transmission is typically used for long-distance signal transmission.
[General]
One component or path in a system, the failure of which would make the system inoperable.
[Data Security]
A form of centralized authentication employing a single set of credentials that are used transparently to perform subsequent authentications on behalf of the users.
[Hardware]
A memory cell that stores a single bit of data.
[Long-Term Retention]
Acronym for Self-contained Information Retention Format.
[Management] [Standards] [Storage System]
1. Acronym for Service Incident Standard.
2. Acronym for Single Instance Storage.
[General]
Acronym for Service Level Agreement.
[Hardware]
Acronym for Single-Level Cell
[General]
Acronym for Service Level Objective.
[Management]
Acronym for Service Location Protocol.
[SCSI]
A collection of ANSI standards and proposed standards that define I/O interconnects primarily intended for connecting storage subsystems or devices to hosts through host bus adapters.
Originally intended primarily for use with small (desktop and desk-side workstation) computers, SCSI has been extended to serve most computing needs, and is arguably the most widely implemented I/O interconnect in use today.
[Hardware]
Various connectors and form factors related to computers.
[Hardware]
A fiber optic socket and plug connector used by Fibre Channel and other technologies.
[Storage System]
An I/O, read, or write request that specifies the transfer of a relatively small amount of data.
‘Small' usually depends on the context, but most often refers to 8 KBytes or fewer. See large I/O request.
[File System] [Network]
Acronym for Server Message Block.
[Management]
Abbreviation for System Management Bus.
[Management] [Network]
1. The Storage Networking Industry Association's (SNIA) Storage Management Initiative (SMI).
SMI develops and standardizes interoperable storage management technologies, including providing conformance testing for products.
2. Acronym for Structure of Management Information.
[Standards]
Acronym for Storage Management Initiative Specification.
[Standards]
Acronym for Society of Motion Picture and Television Engineers.
[Storage System]
Acronym for shingled magnetic recording.
[Data Management]
A point in time copy of a defined collection of data.
Clones and snapshots are full copies. See delta snapshot. Depending on the system, snapshots may be of files, LUNs, file systems, or any other type of container supported by the system.
[Storage System] [Standards]
Acronym for Storage Networking Industry Association.
[Data Security]
A software tool for auditing and identifying network traffic packets.
[Network] [Management]
Acronym for Simple Network Management Protocol.
[Network]
Acronym for Simple Name Server.
[Hardware]
Acronym for System on a Chip.
[Data Security]
Act of manipulating people into performing actions or divulging confidential information [ISO/IEC 27033-3:2010]
Examples include tricking people into downloading and executing files that appear to be benign but are actually malicious, revealing passwords, etc.
[Standards]
An industry association whose goal is to standardize television and motion picture industry information interchange protocols.
Acronym for Start Of Frame.
[File System]
Synonym for symbolic link.
A zone consisting of zone members that are permitted to communicate with each other via the fabric.
Soft zones are typically implemented through a combination of name server and Fibre Channel protocol when a port contacts the name server, the name server returns information only about Fibre Channel ports in the same zone(s) as the requesting port. This prevents ports outside the zone(s) from being discovered and hence the Fibre Channel protocol will not attempt to communicate with such ports. In contrast to hard zones, soft zones are not enforced by hardware; e.g., a frame that is erroneously addressed to a port that should not receive it will nonetheless be delivered. Well-known addresses are implicitly included in every zone. See zone, hard zone.
[Computer System]
An application combined with an operating environment designed to run on industry standard hardware.
If a vendor installs the software appliance on hardware prior to customer delivery, the offering is considered an appliance.
[Services]
Delivery over a network, on demand, of the use of an application.
[Management]
A virtualized data center with a service management interface.
Application requirements determine the service levels provided.
[Storage System]
Virtualized storage with a service management interface.
SDS includes pools of storage with data service characteristics that may be applied to meet the requirements specified through the service management interface.
An information category indicated in a Fibre Channel frame header.
An information category indicated in a Fibre Channel frame header.
[Storage System]
Synonym for solid state storage array.
[Storage System]
Deprecated synonym for Solid State Drive.
[Storage System]
A storage device in which the storage capability is provided by Solid State Storage.
Abbreviated as SSD.
[Storage System]
A storage capability built from solid state electronics.
[Storage System]
A storage array that uses solid state storage and may contain other storage media.
[Computer System]
All hardware and software components that are exercised during a test to verify functional behavior or determine performance characteristics.
The solution under test comprises the infrastructure including software components, application(s), test system(s), and the system(s) under test.
See also system under test and test system.
[Network]
Shorthand for Synchronous Optical Network.
A number in a Fibre Channel frame that identifies the source of the frame.
See D_ID.
[Storage System]
Deprecated synonym for capacity optimization.
[Storage System]
An object reserved for the purpose of substitution for a like object in case of that object's failure.
[File System]
A file that has empty (unwritten and unallocated) data regions, which on reading back are implicitly filled with bytes containing the value zero (0x00).
On some file systems all files are implicitly sparse.
Any transmission character that is valid in the transmission code but does not correspond to a valid data byte.
Special characters are used to denote special functions.
A code that, when encoded using the rules specified by the transmission code, results in a special character.
Special codes are typically associated with control signals related to protocol management (e.g., K28.5).
[SCSI]
Acronym for SCSI Parallel Interface.
[Storage System]
Synonym for full volume transfer rate.
[Storage System]
1. An I/O request to a virtual disk that requires two or more I/O operations to satisfy, because the virtual data addresses in the request map to more than one extent on one or more disks.
2. An application I/O request that is divided into two or more sub-requests by a file system or other operating system component because the amount of data requested is too large for the operating environment to handle as a unit.
[Storage System] [Data Recovery]
1. [Storage System] Any of a class of point in time copy implementations or the resulting copies in which the storage for the copy is synchronized to the source of the copy and then split.
A split mirror copy occupies as much storage as the source of the copy.
2. [Data Recovery] A method for generating a frozen image of a set of data.
[General]
Acronym for Single Point Of Failure.
[Data Security]
Unauthorized use of legitimate identification and authentication data to mimic a subject different from the attacker.
Impersonating, masquerading, piggybacking and mimicking are forms of spoofing.
Acronym for Submission Queue.
[NVMe]
Acronym for Submission Queue Entry.
Acronym for Sequence Recipient.
[Hardware]
Acronym for Static Random Access Memory.
[Management]
Acronym for Storage Resource Management.
[Storage System]
Acronym for Solid State Drive.
[iSCSI]
Shorthand for iSCSI Session Identifier.
[Data Security]
Acronym for Secure Sockets Layer.
[Data Security]
Acronym for Single Sign On.
[Data Security]
Acronym for Security Target.
[SCSI]
Acronym for SCSI Trade Association.
[Storage System]
Stable storage is persistent storage where data survives: 1. Repeated power failures, including cascading power failures, 2. Single hardware failures (of any board, power supply, etc. but not including media), 3. Repeated software crashes, including reboot cycle, and 4. A minimum number of hours without external power.
For more information on stability evaluation it is suggested to read:
- SNIA Emerald Specification annex C
- Description of Stable Storage for SPEC SFS 2014
[Data Recovery]
A removable media drive that is not associated with a media stacker or robot.
[Standards]
An I/O or network interconnect whose specifications are readily available to the public, and that can therefore easily be implemented in a vendor's products without license or royalty payments.
Also called an open interconnect.
[Network]
A physical network configuration in which every node is connected directly to, and only to, a central point; all communications pass through the central point, which may be a hub or a switch.
[Computer System]
The condition of a system at a point in time.
Examples of systems that have states could be a program, software routine, or hardware component.
[Computer System]
A property of a system where operation of that system is dependent on state.
Examples of systems that are stateful include SMB and NFS v4.1.
[Computer System]
A property of a system where operation of that system is independent of state.
Examples of systems that are stateless include NFS v3 and HTTP.
[Hardware]
Byte-addressable computer memory that maintains state indefinitely given continuous power.
[General]
A function that records data and supports retrieval.
[Network] [Storage System]
1. A network whose primary purpose is the transfer of data between computer systems and storage devices and among storage devices.
A SAN consists of a communication infrastructure, which provides physical connections, and a management layer, which organizes the connections, storage devices, and computer systems so that data transfer is secure and robust. The term SAN is usually (but not necessarily) identified with block I/O services rather than file access services.
2. A storage system consisting of storage elements, storage devices, computer systems, and/or appliances, plus all control software, communicating over a network.
The SNIA definition specifically does not identify the term SAN with Fibre Channel technology. When the term SAN is used in connection with Fibre Channel technology, use of a qualified phrase such as "Fibre Channel SAN" is encouraged. According to this definition, an Ethernet-based network whose primary purpose is to provide access to storage devices would be considered a SAN. SANs are sometimes also used for system interconnection in clusters.
[Storage System]
A collection of storage devices from one or more commonly accessible storage subsystems, combined with a body of control software that presents an abstracted view of the storage.
[Storage System]
A device for handling storage requests that includes a processor or sequencer programmed to autonomously process a substantial portion of I/O requests directed to storage devices.
Aggregating RAID controllers and filers are examples of storage controllers.
[Storage System]
Any storage element or aggregation of storage elements designed and built for data storage and delivery.
[Storage System]
A collection of storage resources and supporting software and interfaces that are managed as a unit.
[Storage System]
The ratio of a storage system's effective capacity to its raw capacity.
An estimated efficiency calculation is permissible using estimated effective capacity.
The storage efficiency of a system is normally low when it is new. On a capacity optimizing system efficiency generally increases as the system is loaded with data. There is no way to precisely predict the storage efficiency of a loaded capacity optimizing system before data is loaded onto it.
[Storage System]
Any component that is used to build storage devices and which contributes to persistent data storage and delivery.
Storage elements are components of storage devices. Examples of a storage element include: disk drive, flash memory, tape cartridge, tape drive, and library.
[Storage System]
Making multiple storage systems appear to a user as a single system.
[Storage System]
The ability of storage devices, products, or systems to work together in a correct, predictable and interchangeable fashion.
[Storage System]
The material in a storage device on which data is recorded.
Storage media includes electrical (e.g., solid state), magnetic (hard disk, tape), and optical media.
[General] [Storage System]
1. An individual that makes prophesies regarding the storage industry.
2. See storage media.
[Storage System] [Network]
The practice of creating, installing, administering, or using networks whose primary purpose is the transfer of data between computer systems and storage elements and among storage devices.
[Network] [Standards] [Storage System]
A 501(c)(6) association of producers and consumers of storage networking products whose goal is to further storage networking technology and applications.
[Storage System]
Stable storage that includes any combination of hardware and software (e.g., RAID, NVRAM, disk sparing and background disk scrubbing or media scan) that assures that all committed IO operations will be preserved in the event of power loss or storage device failure.
[Management]
The category of resources that encompasses storage services.
[Management]
Management of physical and logical storage resources, including storage elements, storage devices, appliances, virtual devices, disk volume and file resources.
[Data Security]
Application of physical, technical, and administrative controls to protect storage systems and infrastructure as well as the data stored (3.50) within them. [ISO/IEC 27040]
Storage security is focused on protecting data (and its storage infrastructure) against unauthorized disclosure, modification, or destruction while assuring its availability to authorized users. These controls may be preventive, detective, corrective, deterrent, recovery, or compensatory in nature.
[Management]
A set of functions that provide storage.
[Storage System]
An integrated collection of (a.) storage controllers and/or host bus adapters, (b.) storage devices, CD-ROM drives, tape drives, and libraries, and (c.) any required control software, that provides storage services to one or more computers.
[Storage System]
The power efficiency of a storage system, where input power is measured at the wall socket and output power is measured at the power inputs to the disks, fans, robotics and electronics.
Measurement points of interest include the idle and maximum activity states.
[Standards]
A hierarchical categorization of storage networking products based on capacity, availability, port count and other attributes.
The SNIA Emeraldâ„¢ Power Efficiency Measurement Specification presents a storage taxonomy.
[Storage System]
Storage space that has availability, performance, and cost characteristics that justify the movement of data between it and other storage tiers based on the requirements of the stored data.
[Storage System]
1. The act of abstracting, hiding, or isolating the internal function of a storage (sub) system or service from applications, compute servers or general network resources for the purpose of enabling application and network independent management of storage or data.
2. The application of virtualization to storage services or devices for the purpose of aggregating, hiding complexity or adding new capabilities to lower level storage resources.
Storage can be virtualized simultaneously in multiple layers of a system, for instance to create HSM like systems.
[Network]
A switching technique that requires buffering an entire frame before it is routed.
A new sequence initiated by a Sequence Initiator in any class of service for an exchange while it already has sequences open for that exchange.
[Storage System]
The consecutively addressed blocks in a single extent.
A disk array's controller uses strips to map virtual disk block addresses to member disk block addresses. Also known as stripe element.
[Storage System]
Synonym for stripe depth.
[Storage System]
The set of strips at corresponding locations of each member extent of a disk array that uses striped data mapping.
The strips in a stripe are associated with each other in a way (e.g., relative extent block addresses) that allows membership in the stripe to be quickly and uniquely determined by a computational algorithm. Parity RAID uses stripes to map virtual disk block addresses to member extent block addresses.
[Storage System]
1. The number of blocks in a strip in a disk array that uses striped data mapping.
2. The number of consecutively addressed virtual disk blocks mapped to consecutively addressed blocks on a single member extent of a disk array.
[Storage System]
The number of blocks in a stripe.
A striped array's stripe size is the stripe depth multiplied by the number of member extents. A parity RAID array's stripe size is the stripe depth multiplied by the number of member extents less the number of parity extents.
[Storage System]
A disk array with striped data mapping but no redundancy for failure protection.
Striped arrays are sometimes used to improve I/O performance on data that is of low value or easily replaced. Virtualizers may also use simple striping of the extents that they import, on the grounds that the underlying storage is responsible for data protection.
[Storage System]
Synonym for striped array.
[Storage System]
1. Short for data striping.
Also known as RAID Level 0 or RAID 0, striping is a mapping technique in which fixed-size consecutive ranges of virtual disk data addresses are mapped to successive array members in a cyclic pattern.
2. A network technique for aggregating the data transfer rates of several links between the same pair of nodes.
A single data stream can be spread across the links for higher aggregate data transfer rate. Sometimes called port aggregation.
[Management] [Network]
A notation for setting or retrieving management variables over SNMP.
SNMP queries are in the form of GET requests for one or more Object IDs (OIDs), which take the form 1.3.1.1.4.6.123.1.1.0; an encoding called ASN.1 is used to transmit both request and reply. The SMI specnot to be confused with the SNIA's Storage Management Initiativespecifies the schema used in the OID strings.
[Data Management]
Data that is organized and formatted in a known and fixed way.
The format and organization are customarily defined in a schema. The term structured data is usually taken to mean data generated and maintained by databases and business applications.
[File System]
A directory in a hierarchical directory tree whose parent is a directory.
[Storage System]
A form of data deduplication that operates at a finer granularity than an entire file or data object.
[Data Security]
In the context of access control or authorization, an entity whose access or usage is controlled.
[NVMe]
A fixed size entry in an SQ that contains a single command.
[General]
The assumption of a component's function in a system by a functionally equivalent component.
[SCSI]
A method used by SAS expanders that forwards connection requests for unknown (i.e., not directly attached) devices via special designated phy links to another more authoritative expander.
The more authoritative expander is usually, but does not have to be, the "root" expander.
[Computer System]
Shorthand for solution under test.
[General]
The installation of a replacement unit in place of a defective unit in a system.
Units are any parts of a system that may either be field replaceable (FRUs) by a vendor service representative or consumer replaceable (CRUs). A physical swap operation may be cold, warm, or hot, depending on the state in which the disk subsystem must be in order to perform it. A functional swap operation may be an auto swap or it may require human intervention.
[Network]
A network infrastructure component to which multiple ports attach.
Unlike hubs, switches typically have internal bandwidth that is a multiple of link bandwidth, and the ability to rapidly switch port connections from one to another. A typical switch can accommodate several simultaneous full link bandwidth transmissions between different pairs of ports. See hub.
[Computer System]
Synonym for failed over.
A Name-Identifier that is associated with a Fibre Channel switch or bridge name.
[Storage Management]
A SNIA open standard for managing data and storage services.
Swordfish is an extension of the Redfish specification that enables simple, scalable, and interoperable management of storage resources, ranging from direct attached storage to complex enterprise class storage servers.
[Storage Management]
A Redfish service that conforms to requirements of the Swordfish specification.
[Storage Management]
A Redfish service entry point through which a particular instance of a Swordfish Service is accessed.
[File System]
A special type of file that can be used to redirect a file or directory path transparently to another file or directory that may be on another system.
Also known as symlink or soft link. Symbolic links differ from hard links in that deletion of the underlying file causes them to be "broken", and subsequent attempts to traverse them fail.
[File System]
Shorthand for a symbolic link.
[Data Security]
Cryptography that uses a symmetric cryptosystem.
[Data Security]
A cryptographic algorithm in which the same key is used to encrypt and decrypt a single message or block of stored information.
Keys used in a symmetric cryptosystem must be kept secret, yet are required on both ends of a protocol exchange. They are commonly used on a per-session basis by layered protocols such as TLS and SSL.
[Computer System]
Deprecated synonym for in-band virtualization.
[General]
1. A receiver's identification of a transmission word boundary.
2. The act of aligning or making two entities be equivalent at a specified point in time.
[Data Management]
In the context of data replication, to establish an identical copy of the user data on the primary volume onto the secondary volume.
[Storage System]
Deprecated synonym for synchronous replication.
[Computer System]
Operations that have a fixed time relationship to each other.
Most commonly used to denote I/O operations that occur in time sequence, i.e., a successor operation does not occur until its predecessor is complete.
[Network]
A standard for optical network elements and transmission.
SONET provides modular building blocks, fixed overheads, integrated operations channels, and flexible payload mappings. Basic SONET provides a data transfer capacity of 51.840 megabits/second. This is known as OC-1. Higher data transfer rates that are n times the basic rate are available (known as OC-n). OC-3, OC-12, OC-48, and OC-192 are currently in common use.
[Storage System]
A replication technique in which data must be committed to stable storage at both the primary site and the secondary site before the write is acknowledged to the host.
[Computer System]
A printed circuit module containing mounting devices for processor(s), memory, and adapter cards, and implementing basic computer functions such as memory access, processor and I/O interconnect clocking, and human interface device attachment.
[Hardware]
Hardware and/or software failure that causes the system to be non-functional.
[Computer System]
The disk on which a computer system's operating software is stored.
The system disk is usually the disk from which the operating system is bootstrapped (initially loaded into memory). It frequently contains the computer system's swap and/or page files as well, and may also contain libraries of common software shared among several applications.
[Hardware] [Management]
A management bus including hardware based on I2C and the associated protocols.
See I2C.
[Hardware]
A composition of multiple components such as CPU, memory, and I/O interface, that perform as a system and are integrated into a single integrated circuit.
[Computer System]
The ability of a service, application or system to run in more than one environment.
[General]
An entity being tested to verify functional behavior or determine performance characteristics.
See also solution under test and test system.
The Source_ID, a three-byte field that contains the address identifier of the source Nx_Port.
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