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AIX Version 4.3 Kernel and Subsystems Technical Reference, Volume 2

SCIOINQU (Inquiry) SCSI Adapter Device Driver ioctl Operation


Provides the means to issue an inquiry command to a SCSI device.


The SCIOINQU operation allows the caller to issue a SCSI device inquiry command to a selected adapter. This command can be used by system management routines to aid in configuration of SCSI devices.

The arg parameter for the SCIOINQU operation is the address of an sc_inquiry structure. This structure is defined in the /usr/include/sys/scsi.h file. The sc_inquiry parameter block allows the caller to select the SCSI and LUN IDs to be queried.

The SC_ASYNC flag byte of the parameter block must not be set on the initial call to this operation. This flag is only set if a bus fault occurs and the caller intends to attempt more than one retry.

If successful, the returned inquiry data can be found at the address specified by the caller in the sc_inquiry structure. Successful completion occurs if a device responds at the requested SCSI ID, but the returned inquiry data must be examined to see if the requested LUN exists. Refer to the Small Computer System Interface (SCSI) Specification for the applicable device for the format of the returned data.

Note: The SCSI adapter device driver performs normal error-recovery procedures during execution of this command.

Return Values

When completed successfully this operation returns a value of 0. Otherwise, a value of -1 is returned and the errno global variable is set to one of the following values:

EFAULT Indicates that a bad copy between kernel and user space occurred.
EINVAL Indicates that a SCIOSTART command was not issued prior to this command.
EIO Indicates that an unrecoverable I/O error has occurred. If EIO is returned, the caller should retry the SCIOINQU operation since the first command may have cleared an error condition with the device. In case of an unrecovered error, the adapter error-status information is logged in the system error log.
ENOCONNECT Indicates that a bus fault has occurred. The caller should respond by retrying with the SC_ASYNC flag set in the flag byte of the passed parameters. If more than one retry is attempted, only the last retry should be made with the SC_ASYNC flag set. Generally the SCSI adapter device driver cannot determine which device caused the SCSI bus fault, so this error is not logged.
ENODEV Indicates that no SCSI controller responded to the requested SCSI ID. This return value implies that no LUNs exist on the requested SCSI ID. Therefore, when the ENODEV return value is encountered, the caller can skip this SCSI ID (and all LUNs on it) and go on to the next SCSI ID. This condition is not necessarily an error and is not logged.
ENOMEM Indicates insufficient memory is available to complete the command.
ETIMEDOUT Indicates that the adapter did not respond with a status before the internal command time-out value expired. On receiving the ETIMEDOUT return value, the caller should retry this command at least once, since the first command may have cleared an error condition with the device. This error is logged in the system error log.


/dev/scsi0, /dev/scsi1, ..., /dev/scsin Provide an interface to allow SCSI device drivers to access SCSI devices/adapters.
/dev/vscsi0, /dev/vscsi1,..., /dev/vscsin Provide an interface to allow SCSI-2 Fast/Wide Adapter/A and SCSI-2 Differential Fast/Wide Adapter/A device drivers to access SCSI devices or adapters.

Related Information

The rmt SCSI device driver, scdisk SCSI device driver, SCSI Adapter device driver.

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