|
NAME | SYNOPSIS | CONFIGURATION | DESCRIPTION | FILES | COLOPHON |
SD(4) Linux Programmer's Manual SD(4)
sd - driver for SCSI disk drives
#include <linux/hdreg.h> /* for HDIO_GETGEO */
#include <linux/fs.h> /* for BLKGETSIZE and BLKRRPART */
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.
The following ioctls 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 ioctl(2)
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 fdisk(1), efdisk(1), and lilo(1). If
the geometry information is not available, zero will be
returned for all of the parameters.
BLKGETSIZE
Returns the device size in sectors. The ioctl(2) parameter
should be a pointer to a long.
BLKRRPART
Forces a reread of the SCSI disk partition tables. No
parameter is needed.
The SCSI ioctl(2) operations are also supported. If the
ioctl(2) parameter is required, and it is NULL, then ioctl(2)
will fail with the error EINVAL.
/dev/sd[a-h]: the whole device
/dev/sd[a-h][0-8]: individual block partitions
This page is part of release 4.12 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2012-05-03 SD(4)
Pages that refer to this page: ioctl(2), ioctl_console(2), hd(4), hpsa(4)