Introduction to common terminology of computer hard disk

1. Tracks, cylinders and sectors

The structure of the hard disk disc group is shown in Figure 1.

The track (Track) is a concentric 阏 trajectory formed when the head of the hard disk 屮 reads and writes data on the disc surface. The track of the hard disk is compiled from the outermost ring into "0", "1", and so on. A hollow cylinder is formed if any of the same tracks on each side of the disc of the hard disk are 屮, and the hollow cylinder is called a cylinder (Cylinder) in the disk technology 屮, that is, all tracks of the same position of the head are composed of columns. If you divide each track on the platter evenly into segments, each section is a sector (sector). Currently used hard disk each track is divided into 64 sectors, the number is 0~63, the hard disk after each sector format of the same capacity and floppy disk, are 512B.

The "0" track is located in a very mainbootrecorder location on the hard disk, and the main boot record area MBR (, master boot record) of the hard disk is in this location. The MBR is located on the hard disk's 0-track 0-cylinder 1-sector, which holds the hard disk Master bootstrapper and the hard disk partition table. In a total of 512B hard drive main lead pollution record area, 446B belongs to the hard disk main boot program, 64B belongs to the Hard Disk Division table, two bytes (55AA) belong to the branch end sign. Towel This can be seen, "0" track once damaged, will make the hard disk's main boot and partition table information is severely damaged, resulting in hard drive cannot be lifted. "0" Track damage also domain on the hard drive bad, but because its position is very important, once damaged, it will make the hard drive can not boot.

When the hard disk is not working, the area where the head is parked, usually specifies a cylindrical surface near the spindle as the Fu land area. The landing area does not store data and can avoid data loss caused by a hard drive when it is shaken and when the head of an emergency landing is on or off. The hard drive will automatically stop the head in the area when the power is off.

2, the hard disk interface

The hard disk interface type has IDE (Intergrateddiscelectronics, integrated electronic disk), SCSI (smallcomputersysteminterface, small computer system interface), SATA ( Serialadvancedtechnologyattachment, serial Gao level addition technology) three kinds.

(1) IDE interface

The IDE's intention is to put the controller into the hard drive or the optical drive. The IDE interface is also called ATA (Advancedtechnologyattachment, Advanced update Technology) interface, the reference of ATA interface makes IDE hard disk interface standard is unified.

(2) SATA interface

The SATA interface is a serial interface that transmits data sequentially and transmits only 1-bit data at a time. Serial ATA hard drive uses 7-core data cables, 15-core power cords.

SATA connect U using Point-to-Point transport protocol, a computer connected to two hard drive inches does not require the hard drive to master, from jumper settings. In addition, SATA interfaces are no longer subject to a single channel connection to only two hard drives, and can simultaneously connect multiple hard disks, which are not comparable to traditional parallel ATA interfaces. It supports not only hard drives, but also CDs, DVDs and other storage devices.

(3) SCSI interface

The SCSI interface is a total line interface that is suitable for multitasking operating systems and is typically used in servers.

3. Partition table

After a hard drive has been dagger and advanced formatted, will be in the operating system to create a partition table, record some of the information, such as the size of the hard disk, hard disk start cylinder and knot reined cylinder distribution, hard disk boot area, file allocation table, root directory and data area, such as a series of data. The data composition of the partitioned table can be summarized as follows.

The ① partition table is created on the No. 0 cylinder, No. 0 track, and 1th sector of the hard disk.

② records the operating system's data.

③ records the number of C (cylinder), H (head), S (sector) of the partition's hard disk.

④ The starting Sector area code, the end sector area code, and the capacity for the record allocation column.

⑤ record the bootable hard drive.

⑥ establishes the boot area.

⑦ establishes the file allocation table (FAT).

⑧ establishes the root directory.

⑨ set up a data storage area.