In all categories hard disks there is no fundamental difference depending on who is the manufacturer. It can also be said otherwise - while the hard disk is working it doesn't matter who is the manufacturer.
The main reason for the occurrence of BAD - sectors is the process of aging of the magnetic surface of the hard disk. So they arise as a result of external mechanical and thermal effects on the hard disk. Most often bad sectors appear when your computer is in applied mechanical shock on it or there are vibrations.
This is due to the fact that the carrier in which is working for restoring the information should remain unchanged to maximum until the client verify the existence and the effectiveness of the recovered data. If during the process of checking occur any questions about the restored information the work can continue. If the disk status is changed (saving the recovered data), the possibility for continuing working in case of arising errors is excluded.
Minimum addressable unit for saving information on disk storage devices. For most of the devices the sector size is 512 bites (for example hard devices) or 2048 bites (for example, optical devices).
Service information (SI) - a set of micro programs stored on the hard drive by the manufacturer that ensure the operation of the device. Many objects of the service information are unique and its destruction can be essential for repairing the hard disk and restoring data from it. It is even possible functioning disk to stop working.
In data recovery from hard disk with different damages (damage on the control board, destruction of the service information, failure in the block of the magnetic heads, etc.). Such parts can be taken from exactly the same hard drive, which is called 'donor'.
HDD (Hard Disk Drive), HMDD (Hard Magnetic Disk Drive) - volatile, rewritable computer storage device. This is the main way to store data in almost all modern computers.
Flash Drive (UFD) - information carrier that uses flash memory for storing data and is connected to a computer or other reader by a standard USB connector. Synonyms: flash, flash memory, flash drive, thumb drive.
CD (Compact Disk - an optical information carrier in the form of a disk with a hole in the center from which the information is read by dint of a laser.
DVD (Digital Versatile Disk - digital multipurpose drive) - a carrier of information in the form of a disk, similar to the CD, but with the ability to store more information thanks to the used laser with a shorter wavelength than which is used in the normal compact disk. Synonyms: compact, compact disk, CD, CD-Rom.
FDD (Floppy Disk Drive) - a portable magnetic data carrier, used for multiple records and saving data with relatively small volume.
SSD (Solid State Disk) - volatile, rewritable computer memory devices without moving parts. Currently are used mainly notebooks and ultra mobile computers where the battery's life is essential - because of the low electricity consummation and they are absolutely noiseless because there are no moving parts. Most important - they are not influenced by vibrations and mechanical shock.
File System - rules that determine the way of organization, storage and naming the data that is stored in the information carriers. It defines the form of a physical information storage that is usually grouped in the kind of files. Specific file system determines the size of the file name, the maximum possible file size, certain file attributes. Some file systems provide additional possibilities such as access differentiation or encrypt files.
FAT (File Allocation Table - a table for placing files) - file system used in many operating systems. FAT is supported by all versions of Windows and many systems UNIX. FAT is prevalent in memory cards for digital cameras and USB flash.
NTFS (New Technology Fie System) - a new technology of the file system - a standard file system for operating systems Microsoft Windows NT, Windows 2000, Windows XP, Windows Vista and Windows Server.
MFT (Master File Table - an index of all files of the volume) - master file table (a database that stores information about the contest of the volumes of NTFS, which is a table whose rows correspond to the files of the volume, and the columns - to the file attributes).
HFS (Hierarchical File System) - a file system developed by Apple for use of computers running the operating system Mac OS.
HFS+ file system developed by Apple to replace previously used HFS. HFS+ can be seen as an enhanced version of HFS with advanced capabilities for Mac OS.
ExtFS (Extended File System) - the first file system designed especially for the operating systems Linux.
Ext2 (second extended file system) - file system for operating systems Linux. It is developed to replace the Extended File System.
Ext3 (third extended file system) - an improved file system used in the operating system Linux. Ext3 is a server version of Ext2 with a support of a journaling file system, but retaining the basic architecture of Ext2.
Ext4 (fourth version of extended file system) - file system used in the operating systems with a kernel on Linux, developed on the base of Ext3. Its most important characteristic is increasing the maximum size of a disk partition. Besides, there is a mechanism in Ext4 for extent file saving (new information is added to the end of a predetermined divided area adjacent to the file), which reduces the fragmentation and improves the productivity.
UFS (Unix File System) - file system designed for operating systems such as BSD and used in a revised and extended form as main operating system in (FreeBSD, OpenBSD, NetBSD).
XFS - a high-productive file system. XFS differs from the other file systems by the fact that it was originally designed for use in very large disks (more than 2 terabytes).
ReiserFS - file system developed specially for Linux. ReiserFS is usually the word used for the third version. Characteristics of ReiserFS: an opportunity to collect many small files in one block for prevent fragmentation and loss of disk space, ability for changing the size of the file system 'on the fly'.
Reiser4 - file system ReiserFS (fourth version) developed especially for Linux. It has the following advantages: it gives the opportunity for performing the options in the file system, either completely, or at all, but not half, which increase the reliability of data storage, more efficient use of space, since the small files are saved together on the base of a plugin that allows the inclusion of additional functions without formatting the disk.
Raid (Redundant Array of Inexpensive Disks) - additional array of independent disks. It serves for increasing the reliability of data storage and /or increasing the speed of reading writing data (RAID 0). Synonyms: array, raid.
ATA (Advanced Technology Attachment) - a parallel interface for connecting storage devices (hard drives and optical devices) to your computer. Different versions of ATA are known as IDE, EIDE, ATAPI.
SATA (Serial ATA) - serial interface for data exchange with information carriers (usually with hard disks). SATA is a parallel interface of ATA (IDE).
SCSI (Small Computer Systems Interface) - an interface for uniting in one link different in their purpose devices such as hard drives, magneto-optical disks, CD devices, DVD, tape drives, scanners, printers, etc. SCSI is widely used in servers, high-productive workstations. RAID arrays of servers are often made of hard drives with SCSI interface.
SAS (Serial Attached SCSI) - a computer interface designed for exchanging data with devices such as hard drives optical disk drives, etc. SAS uses serial interface for operation with a direct connection of the devices. SAS is designed to replace the parallel SCSI interface by allowing achieving higher throughput than SCSI, and while is compatible with SATA.
Fibre Channel - a high-speed interface for data transfer, used for connecting workstations, mainframes and devices for data storage. Parts of the devices can be connected directly to each other (point-to-point), to be included in a controlled chain (arbitrated loop), or in a switched network.
NAS (Network Attached Storage) - a system for network storage of data that is connected to the network Ethernet via the protocol TCP/IP. Often disks in NAS are united in RAID.
