Disk Structure:
Disk drives are addressed as large 1-dimensional
arrays of logical blocks, where the logical block is the smallest unit of
transfer the 1-dimensional array of logical blocks is mapped into the sectors
of the disk sequentially – Sector 0 is the first sector of the first track on
the outermost cylinder – Mapping proceeds in order through that track, then the
rest of the tracks in that cylinder, and then through the rest of the cylinders
from outermost to innermost.
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| Physical Disk Structure |
Cylinder
The disc that makes up the hard disk is divided into tracks; tracks of all discs which have same track value are called a cylinder, so the cylinder is a pile of tracks with same track value of a hard disk.
The disc that makes up the hard disk is divided into tracks; tracks of all discs which have same track value are called a cylinder, so the cylinder is a pile of tracks with same track value of a hard disk.
Head
Normally, a disc has two heads for reading or writing data, one is for the top and the other one is for the opposite side; the head value means the disc location and side.
Sector
A track is composed of sectors and the number of sectors of all tracks on the hard disk is the same.Sector is the minimal storage unit of a hard disk; the size of one sector is always 512 bytes (rarely, it might be 1024, 2048 or 4096 bytes in some special hard disks).
Normally, a disc has two heads for reading or writing data, one is for the top and the other one is for the opposite side; the head value means the disc location and side.
Sector
A track is composed of sectors and the number of sectors of all tracks on the hard disk is the same.Sector is the minimal storage unit of a hard disk; the size of one sector is always 512 bytes (rarely, it might be 1024, 2048 or 4096 bytes in some special hard disks).
