Originální popis anglicky:
sd - Driver for SCSI Disk Drives
Návod, kniha: Linux Programmer's Manual
#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 re-read of the SCSI disk partition tables. No
parameter is needed.
The scsi(4) ioctls are also supported. If the ioctl(2)
parameter is required, and it is NULL, then ioctl() will return
-EINVAL.
/dev/sd[a-h]: the whole device
/dev/sd[a-h][0-8]: individual block partitions
scsi(4)
