SCSI Primary Commands - 2.pdf

T10/1236-D Revision 20 18 July 20017.3 INQUIRY command7.3.1 INQUIRY command introductionThe INQUIRY command (see table 45) requests that information regarding parameters of the target and acomponent logical unit be sent to the application client. Options allow the application client to request additionalinformation about the target and logical unit (see 7.3.4) or information about SCSI commands supported by thedevice server (see 7.3.5).Table 45 — INQUIRY commandBitByte7 6 5 4 3 2 1 00 OPERATION CODE (12h)1 Reserved CMDDT EVPD2 PAGE OR OPERATION CODE3 Reserved4 ALLOCATION LENGTH5 CONTROLAn enable vital product data (EVPD) bit of one specifies that the device server shall return the vital product dataspecified by the PAGE OR OPERATION CODE field.A command support data (CMDDT) bit of one specifies that the device server shall return the optional commandsupport data specified by the PAGE OR OPERATION CODE field. If the device server does not support returningcommand data and this bit is set to one, the device server shall return CHECK CONDITION status with the sensekey set to ILLEGAL REQUEST and an additional sense code of INVALID FIELD IN CDB. Details of the commandsupport data may be found in 7.3.5.NOTE 11 An application client may receive a CHECK CONDITION status response with the sense key set toILLEGAL REQUEST upon sending an INQUIRY command with the CMDDT bit set to one to some SCSI-2 deviceservers, since this bit was reserved in SCSI-2.If both the EVPD and CMDDT bits are zero, the device server shall return the standard INQUIRY data (see 7.3.2). Ifthe PAGE OR OPERATION CODE field is not zero when both EVPD and CMDDT are zero, the device server shall returnCHECK CONDITION status with the sense key set to ILLEGAL REQUEST and an additional sense code ofINVALID FIELD IN CDB.If both the EVPD and CMDDT bits are one, the device server shall return CHECK CONDITION status with the sensekey set to ILLEGAL REQUEST and an additional sense code of INVALID FIELD IN CDB.When the EVPD bit is one, the PAGE OR OPERATION CODE field specifies which page of vital product data informationthe device server shall return (see 8.4).When the CMDDT bit is one, the PAGE OR OPERATION CODE field specifies the SCSI operation code for which deviceserver shall return command support data (see 7.3.5).The INQUIRY command shall return CHECK CONDITION status only when the device server is unable to returnthe requested INQUIRY data.80 dpANS SCSI Primary Commands - 2 (SPC-2)