User Manual

SCSI Commands Reference Manual, Rev. J 26
www.seagate.com Definitions, Symbols, Abbreviations, Keywords, And Conventions
Copy target device
The name given by the EXTENDED COPY command to a source or destination logical unit (i.e., a copy target device is a logical unit, not a SCSI
target device).
Cyclic redundancy check (CRC)
An error checking mechanism that checks data integrity by computing a polynomial algorithm based checksum.
Data defect list (DLIST)
A list of defects sent by the application client to the device server during a FORMAT UNIT command.
Data-in buffer
The buffer specified by the application client to receive data from the device server during the processing of a command.
Data-out buffer
The buffer specified by the application client to supply data that is sent from the application client to the device server during the processing of
a command.
Default protection information
Values placed into protection information fields if an application client does not specify specific protection information values.‘
Deferred error
A CHECK CONDITION status and sense data that is returned as the result of an error or exception condition that occurred during processing of
a previous command for which GOOD, CONDITION MET, INTERMEDIATE, and INTERMEDIATE-CONDITION MET status has already been returned.
Device server
An object within a logical unit that processes SCSI tasks according to the rules of task management. A detailed definition of a device server may
be found in SAM-5.
Device service request
A request, submitted by an application client, conveying a SCSI command to a device server. A detailed definition of a device service request
may be found in SAM-5.
Device service response
The response returned to an application client by a device server on completion of a SCSI command. A detailed definition of a device service
response may be found in SAM-5.
Device type
The type of peripheral device (i.e., device model) implemented by the device server and indicated by the contents of the PERIPHERAL DEVICE
TYPE field in the standard INQUIRY data.
Direct-access block device
A device that is capable of containing data stored in blocks that each have a unique logical block address.
Domain
An I/O system consisting of a set of SCSI devices that interact with one another by means of a service delivery subsystem.
Element
An addressable physical component of a medium changer SCSI device that may serve as the location of a removable unit of data storage
medium. A detailed definition of an element may be found in SMC-3.
Enabled task state
The only task state in which a task may make progress towards completion. A detailed definition of the enabled task state may be found in
SAM-5.
Error correcting code (ECC)
An error checking mechanism that checks data integrity and enables some errors in the data to be corrected.
Error history I_T nexus
An I_T nexus for which the device server has reserved access to the error history snapshot (see SPC-5).
Error history snapshot
The contents of the error history at a specific point in time (see SPC-5).
Exclusive-or (XOR)
A Boolean arithmetic function on two binary input values that results in an output value of 1 if one and only one of the input values is 1.