[Fibre Channel] A string of eight contiguous bits within FC-P1 that represents a value between 0 and 255.
[Fibre Channel] A received frame containing a valid Start of Frame (SOF), a valid End of Frame (EOF), valid data characters, and proper Cyclic Redundancy Check (CRC) of the Frame Header and Data Field.
[Fibre Channel] A control bit that indicates whether a field is valid.
If a validity control bit indicates that a field is invalid, the value in the field is treated as invalid and ignored.
[Storage System] Acronym for Virtual Block Address.
[Network] Acronym for Virtual Channel Identifier.
[Fibre Channel] Acronym for Vertical Cavity Surface Emitting Laser.
[Standards] Aspects related to a standard (e.g., functions, codes, etc.) not defined by the standard, but offered by a single vendor within the framework of the standard.
Functionality unique to a given vendor may be exposed using standard methods. For example, many vendors offer vendor-specific SNMP MIBs that users of the SNMP standard can use to obtain system information.
[Data Recovery] The object-by-object comparison of the contents of a backup image with the online data objects from which it was made.
[Data Recovery] The maintenance of multiple point-in-time copies of a collection of data.
Versioning is used to minimize recovery time by increasing the number of intermediate checkpoints from which an application can be restarted.
[Fibre Channel] A surface emitting laser source fabricated on a planar wafer with emission perpendicular to the wafer.
[Fibre Channel] [Network] The Name_Identifier of a VE_Port.
[Fibre Channel] Acronym for Virtual Fabric.
[Fibre Channel] Shorthand for Virtual Fabric Identifier.
[Fibre Channel] [Network] The Name_Identifier of a VF_Port.
[Fibre Channel] Short for Virtual Fabric Tagging Header.
[Computer System] Acronym for Virtual Interface Architecture.
Virtual blocks are the atomic units in which a virtual disk’s storage capacity is typically presented by RAID arrays to their operating environments.
[Storage System] The address of a virtual block.
Virtual block addresses are typically used in hosts’ I/O commands addressed to the virtual disks instantiated by RAID arrays. SCSI disk commands addressed to RAID arrays are actually using virtual block addresses in their logical block address fields.
[Network] A unique numerical tag contained in an ATM cell header.
A VCI identifies an ATM virtual channel over which the cell containing it is to travel.
From an application standpoint, a virtual device is equivalent to a physical one. In some implementations, virtual devices may differ from physical ones at the operating system level. E.g., booting from a host based disk array may not be possible.
[Storage System] A set of disk blocks presented to an operating environment as a range of consecutively numbered logical blocks with disk-like storage and I/O semantics.
The term virtual indicates the use of a non Fibre Channel link connecting the VE_Ports.
[Fibre Channel] A Fabric identified by a VF_ID composed of partitions of switches and N_Ports having the properties of: 1) a single Fabric management, 2) independence from all other Virtual Fabrics, e.g., an independent address space.
[Fibre Channel] A value that uniquely identifies a Virtual Fabric among all the Virtual Fabrics that share a set of switches and N_Ports.
[Computer System] An API specification for direct communication among distributed applications developed by Intel, Compaq, and Microsoft.
VIA reduces interprocess communication latency by obviating the need for applications to use processor interrupt or operating system paths to intercommunicate, while maintaining security on the communications path. VIA is interconnect neutral. See Fibre Channel Virtual Interface.
[Network] A logical network that behaves as if it is physically separate from other physical and virtual LANs supported by the same switches and/or routers.
The term virtual indicates the use of a non Fibre Channel link connecting a VN_Port to a VF_Port.
[Network] An eight-bit field in an ATM cell header that denotes the cell over which the cell should be routed.
Multiple Virtual Switches may reside within a Core Switch.
[Storage System] A virtual device with the characteristics of a tape.
[Computer System] The act of integrating one or more (back end) services or functions with additional (front end) functionality for the purpose of providing useful abstractions.
Typically virtualization hides some of the back end complexity, or adds or integrates new functionality with existing back end services. Examples of virtualization are the aggregation of multiple instances of a service into one virtualized service, or to add security to an otherwise insecure service. Virtualization can be nested or applied to multiple layers of a system.
[Data Security] A type of programmed threat; a code fragment (not an independent program) that replicates by attaching to another program, and either damages information directly or causes denial of service.
[Network] Acronym for Virtual Local Area Network.
[Computer System] A property of data yielding the possibility that it will be obliterated if certain environmental conditions are not met.
1. [Storage System] Synonym for virtual disk.
2. [Storage system] A storage element that has been prepared for use.
Examples include tape cartridges and USB thumb drives.
[Storage System] Common term for host-based control software.
[Data Recovery] A logical collection of removable media designated for a given purpose, for example, for holding the copies of a single repetitive backup job, or for backing up data from a given client or set of clients.
[Storage System] Synonym for virtual disk.
[Network] Acronym for Virtual Path Identifier.