SCSI Primary Commands - 2.pdf

18 July 2001 T10/1236-D Revision 203 Definitions, symbols, abbreviations, and conventions3.1 Definitions3.1.1 active condition: When a logical unit is capable of responding immediately to media access requests, andoperations complete in the shortest practical time.3.1.2 additional sense code: A combination of the ADDITIONAL SENSE CODE and ADDITIONAL SENSE CODE QUALIFIERfields (see 7.20.2) in the sense data (see 3.1.47).3.1.3 application client: An object that is the source of SCSI commands. Further definition of an applicationclient may be found in SAM-2.3.1.4 attached medium changer: A medium changer that is attached to and accessed through some other typeof SCSI device. See 5.7.3.1.5 asynchronous event reporting (AER): A mechanism used by a logical unit to signal an initiator that anasynchronous event has occurred. The mechanism for asynchronous event reporting is protocol specific. Adetailed definition of AER may be found in SAM-2.3.1.6 auto contingent allegiance (ACA): One of the conditions of a task set following the return of a CHECKCONDITION status. A detailed definition of ACA may be found in SAM-2.3.1.7 autosense data: The sense data that is automatically delivered to the application client by the device serverin a protocol specific manner when a command completes with a CHECK CONDITION status (see 4.2 andSAM-2).3.1.8 blocked task: A blocked task that is in the blocked state as defined in SAM-2. Tasks become blocked whenan ACA condition occurs. The blocked state ends when the ACA condition is cleared. A detailed definition of theblocked task state may be found in SAM-2.3.1.9 byte: Indicates an 8-bit construct.3.1.10 command: A request describing a unit of work to be performed by a device server. A detailed definition ofa command may be found in SAM-2.3.1.11 command descriptor block (CDB): The structure used to communicate commands from an applicationclient to a device server. A CDB may have a fixed length of up to 16 bytes or a variable length of between 12 and260 bytes.3.1.12 command standard: A SCSI standard that defines the model, commands, and parameter data for a devicetype (e.g., SBC, SCC, SGC, SMC, SSC, MMC, or SES). See clause 1.3.1.13 contingent allegiance (CA): One of the conditions of a task set following the return of a CHECKCONDITION status. A detailed definition of CA may be found in SCSI-2.3.1.14 copy manager: The device server that receives an EXTENDED COPY command and performs theoperation requested.3.1.15 data-in buffer: The buffer identified by the application client to receive data from the device server duringthe execution of a command (see 4.2 and SAM-2).dpANS SCSI Primary Commands - 2 (SPC-2) 5