[Data Security] Acronym for Security Association.
[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.
1. [Fibre Channel] [iSCSI] [Network] Storage Area Network.
This is the normal meaning in SNIA documents.
2. [Computer System] Acronym for Server Area Network, which connects one or more servers.
3. [Computer System] Acronym for System Area Network, an interconnected set of system elements.
[Data Security] Synonym for data shredding.
[Data Security] Acronym for Security Assurance Requirements.
[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.
1. [Management] A collection of information models or data models.
2. [Data Management] Data that describes the organization and format of other data.
Often used with respect to ports, most of which are able to execute scripts of I/O commands autonomously (without policy processor assistance).
2. [Computer System] A sequence of instructions intended to be parsed and carried out by a command line interpreter or other scripting language.
[SCSI] Acronym for Small Computer System Interface.
[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.
New generations of this standard are identified by a numeric suffix; for example the second generation standard is SAM2.
[SCSI] Deprecated synonym for SCSI interconnect.
For example, a SCSI Initiator Device contains one or more SCSI Initiator Ports and zero or more application clients.
[SCSI] A standard for management of environmental factors such as temperature, power, voltage, etc.
[SCSI] A standard for media changer devices (i.e., libraries).
Several versions of SPI, known as SPI, SPI2, SPI3, etc., have been developed. Each version provides for greater performance and functionality than preceding ones.
[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.
[Network] Acronym for Synchronous Digital Hierarchy.
[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.
[Computer System] Organization of data processing components such that multiple users and their computations and data are isolated from and inaccessible to one another, except via authorized channels.
[Data Security] A message digest algorithm that produces a 160 bit digest.
SHA-1 is defined in RFC 3174.
[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).
[Data Security] A simplex "connection" that affords security services to the traffic carried by it.
To secure typical, bi-directional communication between two hosts, or between two security gateways, two Security Associations (one in each direction) are required. In IPsec, a security association is uniquely identified by a triple consisting of a Security Parameters Index (SPI), an IP Destination Address, and a security protocol identifier (Authentication Header or Encapsulating Security Payload).
[Data Security] A set of assurance components (classes and families) that represent a standard way of expressing the assurance requirements for TOEs.
These requirements are drawn from ISO 15408-3:1999, whenever possible.
[Data Security] A collection of people and systems under the control of a single authority, often with a single security policy.
[Data Security] A set of security functional components (classes and families) that represent a standard way of expressing the functional requirements for TOEs.
These requirements are drawn from ISO 15408-2:1999, whenever possible.
[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] A securely identified and verified entity.
[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 computational complexity associated with defeating the protection conveyed by a given cryptographic algorithm.
Security strength is often expressed as a number of bits.
[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.
[Long Term Retention] A self-describing container format, developed by the SNIA, appropriate for the long-term storage of digital information.
[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.
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 could adversely affect the interest or the conduct of an organization’s business or activities, or the privacy to which individuals are entitled.
[Fibre Channel] 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.
[Computer System] Short for Serializer Deserializer.
[General] The transmission of data bits one at a time over a single 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.
[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.
2. [Computer System] 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.
A service level agreement defines parameters for measuring the service, and states quantitative values for those parameters.
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.
1. [SCSI] Acronym for SCSI Enclosure Services.
2. [Standards] Acronym for Solution Exchange Standard.
[Fibre Channel] Abbreviation for Source Fabric_Identifier.
[Data Security] Acronym for Security Functional Requirements.
[Data Security] Acronym for Secure Hash Algorithm 1.
[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 and tapes.
[Data Security] A room or container designed to attenuate electromagnetic radiation.
1. [General] Acronym for Semiconductor Industries Association.
2. [SCSI] Acronym for SCSI Industry Association.
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.
[Storage System] A form of data deduplication that operates at a granularity of an entire file or data object.
[Fibre Channel] [Network] A fiber optic cabling specification that provides for up to 10 kilometer distance between devices.
[Fibre Channel] Optical fiber that is designed for the transmission of a single ray or mode of light as a carrier.
[General] One component or path in a system, the failure of which would make the system inoperable.
[Long Term Retention] Acronym for Self-contained Information Retention Format.
1. [Management] [Standards] Acronym for Service Incident Standard.
2. [Storage System] Acronym for Single Instance Storage.
[General] Acronym for Service Level Agreement.
[General] Acronym for Service Level Objective.
[Management] Acronym for Service Location Protocol.
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.
[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.
1. [Management] 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. [Fibre Channel] [Management] [Network] Acronym for Structure of Management Information.
[Standards] Acronym for Storage Management Initiative Specification.
[Standards] Acronym for Society of Motion Picture and Television Engineers.
[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.
[Network] [Standards] [Storage System] 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.
[Data Security] Use of social rather than technical methods to obtain sensitive information or perform privileged actions.
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.
[Fibre Channel] Acronym for Start Of Frame.
[File System] Synonym for symbolic link.
[Fibre Channel] 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.
[Storage] A shiny ball popular in early 2013.
Consensus on a solid technical definition of this concept has yet to be reached.
[Storage System] Synonym for Solid State Drive.
[Storage System] A storage capability built from solid state electronics.
Form factors and interfaces for solid state drives are typically the same as for traditional disk drives.
[Network] Shorthand for Synchronous Optical Network.
[Storage System] Deprecated synonym for capacity optimization.
[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.
Special characters are used to denote special functions.
1. [SCSI] Acronym for SCSI Parallel Interface.
2. [Data Security] Acronym for Security Parameters Index.
[Storage System] Synonym for full volume transfer rate.
1. [Storage System] 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. [Storage System] 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.
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.
A split mirror frozen image contains a complete copy of data as of the moment of frozen image creation. When a split mirror frozen image has served its purpose, it may be resynchronized with the original data from which it was split, or discarded.
[General] Acronym for Single Point Of Failure.
[Legal] The intentional or negligent destruction, hiding, alteration, withholding or concealment of withholding of evidence relevant to a legal action.
Impersonating, masquerading, piggybacking and mimicking are forms of spoofing.
[Fibre Channel] Acronym for Sequence Recipient.
[Management] Acronym for Storage Resource Management.
[Data Security] Acronym for Secure Remote Password.
[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.
[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.
[Fibre Channel] A group of ordered sets that delineates the beginning of a frame.
[General] A function that records data and supports retrieval.
1. [Network] 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. [Storage System] 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 disks or tapes from one or more commonly accessible storage subsystems, combined with a body of control software.
[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] A collection of storage resources and supporting software and interfaces that are managed as a unit.
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, such as a disk, tape or tape drive, that is used to build storage devices and which contributes to persistent data storage and delivery.
Storage elements are components of storage devices.
[Storage System] A contiguous array of bytes—real or virtual—as exposed by a storage container.
[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.
1. [General] An individual that makes prophesies regarding the storage industry.
2. [Storage System] 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.
[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.
[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 such as disk drives, 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.
[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.
1. [Storage System] 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. [Storage System] 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.
[Fibre Channel] [Network] A switching technique that requires buffering an entire frame before it is routed.
2. [File System] A subfile in the CIFS protocol.
NFSv4 provides equivalent functionality using Named Attributes.
[Storage System] The consecutively addressed blocks in a single extent.
[Storage System] Synonym for stripe depth.
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] Synonym for strip.
[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.
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.
1. [Storage System] Short for data striping.
2. [Storage System] A network technique for aggregating the bandwidth of several links between the same pair of nodes.
A single data stream can be spread across the links for higher aggregate bandwidth. Sometimes called port aggregation.
[Fibre Channel] [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 184.108.40.206.220.127.116.11.1.0; an encoding called ASN.1 is used to transmit both request and reply. The SMI spec—not to be confused with the SNIA's Storage Management Initiative—specifies 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.
[Storage System] A form of data deduplication that operates at a finer granularity than an entire file or data object.
[General] The assumption of a component's function in a system by a functionally equivalent component.
[Network] Acronym for Switched Virtual Circuit.
[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.
[Fibre Channel] [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 failback.
[Computer System] Synonym for failover.
[Computer System] Synonym for failed over.
[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.
[File System] Shorthand for a symbolic link.
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.
2. [General] The act of aligning or making two entities be equivalent at a specified point in time.
An SDH uses a light scrambling of data to remove only the lowest frequency elements with the goal of achieving maximum digital bandwidth use.
[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 bandwidth of 51.840 megabits/second. This is known as OC-1. Higher bandwidths 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.
[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.
[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.
Distinguished from test system.