SD Section: Linux Programmer's Manual (4) Updated: Thu Dec 17 10:15:53 1992 Index   NAME sd - Driver for SCSI Disk Drives   SYNOPSIS #include <linux/hdreg.h> /* for HDIO_GETGEO */ #include <linux/fs.h> /* for BLKGETSIZE and BLKRRPART */   CONFIG The block device name has the following form: sdlp, where l is a letter denoting the physical drive, and p is a number denoting the partition on that physical drive. Often, the partition number, p, will be left off when the device corresponds to the whole drive. SCSI disks have a major device number of 8, and a minor device number of the form (16 * drive_number) + partition_number, where drive_number is the number of the physical drive in order of detection, and partition_number is as follows: partition 0 is the whole drive partitions 1-4 are the DOS "primary" partitions partitions 5-8 are the DOS "extended" (or "logical") partitions For example, /dev/sda will have major 8, minor 0, and will refer to all of the first SCSI drive in the system; and /dev/sdb3 will have major 8, minor 19, and will refer to the third DOS "primary" partition on the second SCSI drive in the system. At this time, only block devices are provided. Raw devices have not yet been implemented.   DESCRIPTION The following ioctl's are provided: HDIO_GETGEO Returns the BIOS disk parameters in the following structure: struct hd_geometry { unsigned char heads; unsigned char sectors; unsigned short cylinders; unsigned long start; }; A pointer to this structure is passed as the parameter. The information returned in the parameter is the disk geometry of the drive as understood by DOS! This geometry is not the physical geometry of the drive. It is used when constructing the drive's partition table, however, and is needed for convenient operation of If the geometry information is not available, zero will be returned for all of the parameters. BLKGETSIZE Returns the device size in sectors. The parameter should be a pointer to a long. BLKRRPART Forces a re-read of the SCSI disk partition tables. No parameter is needed. The ioctls are also supported. If the parameter is required, and it is NULL, then will return -EINVAL.   FILES /dev/sd[a-h]: the whole device /dev/sd[a-h][0-8]: individual block partitions   SEE ALSO   Index NAME SYNOPSIS CONFIG DESCRIPTION FILES SEE ALSO This document was created by using the manual pages. Time: 12:11:43 GMT, March 24, 2025