Appendix a glossary, Appendix a “glossary – StorageTek StorageNet SCSI-3 User Manual
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Appendix A Glossary
Application Client: The source object of the SCSI commands and destination for the
command responses.
Byte: A group of 8 bits.
Command Descriptor Block: The structure of up to 16 bytes in length used to communicate
commands from the application client to a device server.
Critical Condition: An enclosure condition where one or more elements inside the enclosure
have failed or are outside of operational parameters. The element failure makes normal
operation of at least some elements in the enclosure impossible, although some of the
elements inside the enclosure may be able to continue normal operation.
Device: A mechanical, electrical or electronic part in an enclosure.
Device Server: A logical unit object that executes SCSI tasks.
Device Service Request: A request from an application client of SCSI commands to a device
server.
Device Slot: An insertion position in an enclosure for SCSI devices. The position provides
power, signal and control connections for the SCSI device. The position may also provide
protection, automatic insertion, device status LEDs, locking capability, and additional
features to manage SCSI devices in the enclosure.
Device Type: The device type or device model implemented by the device server.
Domain_ID: The domain number uniquely identifies the switch in a Fabric. Normally the
switch domain ID is automatically assigned by the principal switch and may be any value
between 0 and 31. This number may also be assigned manually.
Enclosure: The box, rack or box set that provide power, mechanical protection, external
interfaces and cooling for the SCSI device(s).
Enclosure Services: The services that establishes indictors and controls for the proper
operation and maintenance of devices within the enclosure.
Enclosure Services Device: A SCSI device that monitors and controls enclosure services.
The switches imbedded port.
Initiator: A SCSI device containing application clients that originate device service requests
to be processed by the device servers.