SCSI Primary Commands - 2.pdf

18 July 2001 T10/1236-D Revision 20The Normal ACA Supported bit (NORMACA) of one indicates that the device server supports setting the NACA bit toone in the CONTROL byte of the CDB (see SAM-2). A NORMACA bit of zero indicates that the device server does notsupport setting the NACA bit to one.A hierarchical support (HISUP) bit of zero indicates the target does not use the hierarchical addressing model toassign LUNs to logical units. A HISUP bit of one indicates the target uses the hierarchical addressing model toassign LUNs to logical units. When the HISUP bit is one, the device server shall support the REPORT LUNScommand (see 7.19). When the HISUP bit is zero, the device server may support the REPORT LUNS command.A RESPONSE DATA FORMAT field value of two indicates that the data shall be in the format specified in this standard.Response data format values less than two are obsolete. Response data format values greater than two arereserved.The ADDITIONAL LENGTH field shall specify the length in bytes of the parameters. If the ALLOCATION LENGTH of theCDB is too small to transfer all of the parameters, the ADDITIONAL LENGTH shall not be adjusted to reflect thetruncation.An SCC Supported (SCCS) bit of one indicates that the device contains an embedded storage array controllercomponent. See SCC-2 for details about storage array controller devices. An SCCS bit of zero indicates that thedevice does not contain an embedded storage array controller component.The basic queuing (BQUE) bit shall be zero if the CMDQUE bit is one.When the CMDQUE bit is zero, the BQUE bit shall have the following meaning. A BQUE bit of zero indicates that thedevice does not support tagged tasks (command queuing) for this logical unit. A value of one indicates that thedevice supports, for this logical unit, the basic task management model defined by SAM-2.An Enclosure Services (ENCSERV) bit of one indicates that the device contains an embedded enclosure servicescomponent. See SES for details about enclosure services, including a device model for an embedded enclosureservices device. An ENCSERV bit of zero indicates that the device does not contain an embedded enclosureservices component.A Multi Port (MULTIP) bit of one indicates that this is a multi-port (two or more ports) device and conforms to theSCSI multi-port device requirements found in the applicable standards (e.g., SAM-2, a protocol standard andpossibly provisions of a command set standard). A value of zero indicates that this device has a single port anddoes not implement the multi-port requirements.A medium changer (MCHNGR) bit of one indicates that the device is associated with or attached to a mediumtransport element. See SMC for details about medium changers, including a device model for an attached mediumchanger device. The MCHNGR bit is valid only when the RMB bit is equal to one. A MCHNGR bit of zero indicates thatthe device is not embedded within or attached to a medium transport element.A relative addressing (RELADR) bit of one indicates that the device server supports the relative addressing mode. Ifthis bit is set to one, the linked command (LINKED) bit shall also be set to one; since relative addressing is onlyallowed with linked commands. A RELADR bit of zero indicates the device server does not support relativeaddressing.A linked command (LINKED) bit of one indicates that the device server supports linked commands (see SAM-2). Avalue of zero indicates the device server does not support linked commands.dpANS SCSI Primary Commands - 2 (SPC-2) 85