scsi_ctl.7 (2010 09)

scsi_ctl(7) scsi_ctl(7)

Most SCSI commands have a logical unit number (LUN) ﬁeld. Parallel SCSI implementations on the

HP-UX operating system select logical units via the SCSI

IDENTIFY message. The LUN portion of the

cdb should normally be set to zero, even when the LUN being accessed is not zero.

Use of linked commands is not supported.

Most SCSI commands with a data phase expect the data length information to be included somewhere in

the command bytes. Both the data_length ﬁeld and any cdb data length values must be correctly

speciﬁed to get correct command results.

Very large (or inﬁnite) timeout values can cause a parallel SCSI bus (potentially the entire system) to

hang.

Device and/or bus reset operations can be used to regain a device’s attention when a timeout expires.

Resetting a device can cause I/O errors and/or loss of cached data. This can result in loss of data and/or

system panics.

Obtaining SCSI

INQUIRY data by use of the

SIOC_INQUIRY ioctl instead of by use of the SIOC_IO

ioctl is generally preferable since SCSI implementations on the HP-UX operating system synchronize

access of inquiry data during driver open calls.

Since communication parameters can be affected by device-speciﬁc driver capabilities, device-speciﬁc

driver use might result in communication parameter changes.

The

SIOC_CAPACITY ioctl is not supported by

scsi_ctl because the meaning of capacity is device-

speciﬁc.

FILES

/usr/include/sys/scsi.h

/usr/include/sys/scsi_ctl.h