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Friday, August 8, 2008

Hard disk Logical Structures and File Systems

Hard disk Logical Structures and File Systems

The hard disk is, of course, a medium for storing information. Hard disks grow in size every year, and as they get larger, using them in an efficient way becomes more difficult. The file system is the general name given to the logical structures and software routines used to control access to the storage on a hard disk system. Operating systems use different ways of organizing and controlling access to data on the hard disk, and this choice is basically independent of the specific hardware being used--the same hard disk can be arranged in many different ways, and even multiple ways in different areas of the same disk. The information in this section in fact straddles the fine line between hardware and software, a line which gets more and more blurry every year.

The nature of the logical structures on the hard disk has an important influence on the performance, reliability, expandability and compatibility of your storage subsystem. This section takes a look at the logical structures on the hard disk and how they are set up and used for a typical PC installation. I begin with a discussion of different PC operating systems, and an overview of different file system types. I then go into significant detail describing the major structures and key operating details of the most common PC file system, FAT (FAT12/FAT16/VFAT/FAT32). I talk about utilities used for partitioning and formatting hard disks, and also talk a bit about disk compression (even though it is no longer nearly as important as it once was.) I place special emphasis on how to organize the disk for maximum performance--while not getting bogged down in the minutiae of optimization where it will buy you little.

Most of the focus in this section is on the FAT family of file systems, because these are by far the most commonly used, and also the ones with which I am most familiar. I do mention alternative file systems, but do not go into extensive detail on them, with one exception. Recognizing the growing role of Windows NT and Windows 2000 systems, a separate, comprehensive section has been added that describes the NTFS family of file systems. If you are mostly interested in reading about NTFS, you may want to skip some of the earlier subsections that describe FAT, and skip directly to the NTFS material. Bear in mind, however, that some of the NTFS discussions build upon the descriptions of FAT, since in some ways the file systems are related.

2 comments:

Unknown said...
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Unknown said...

Great article,it is useful information. The hard-disk is a medium for saving the data. It's storing capacity yearly increases. The hard-disk file system generally Fat or NTFS. The FAT file system included different versions such as FAT12, FAT16, Fat32, etc. the sensible components on the hard disk has an important impact on the performance, stability, expandability and interface of your storage space subsystem. FAT file system is always better for regularly use. Market Analysis