Exactly what happens when you defragment your computer?

Answer 1

Defragmentation



In the context of administering computer systems, defragmentation (or defragging) is a process that reduces the amount of fragmentation in file systems. It does this by physically reorganizing the contents of the disk in order to store the pieces of each file close together and in order (contiguously). It also attempts to create larger regions of free space using compaction to impede the return of fragmentation. Some defragmenters also try to keep smaller files within a single directory together, as they are often accessed in sequence.Contents [hide]


Aims of defragmentation

Reading and writing data on a heavily fragmented file system is slowed down as the time needed for the disk heads to move between fragments, and waiting for the disk platter to rotate into position, is often fatal to throughput (see seek time and rotational delay). For many common operations, the performance bottleneck of the entire computer is the hard disk; thus the desire to process more efficiently encourages defragmentation. Operating system vendors often recommend periodic defragmentation in order to keep disk access speed from degrading over time.

Fragmented data also spreads over more of the disk than it needs to. Thus one may defragment in order to compact data storage before splitting a single partition into two or more partitions (for example, with GNU Parted, or PartitionMagic).


Causes and cures

Fragmentation occurs when the operating system cannot or will not allocate enough contiguous space to store a complete file as a unit, but instead puts parts of it in gaps between other files (usually those gaps exist because they formerly held a file that the operating system has subsequently deleted or because the operating system allocated excess space for the file in the first place). As advances in technology bring larger disk drives, the performance loss due to fragmentation squares with each doubling of the size of the drive.[citation needed] Larger files and greater numbers of files also contribute to fragmentation and consequent performance loss. Defragmentation attempts to alleviate these problems.

A defragmentation program must move files around within the free space available in order to undo fragmentation. This is a memory intensive operation and cannot be performed on a file system with no free space. The reorganization involved in defragmentation does not change logical location of the files (defined as their location within the directory structure).

Another common strategy to optimize defragmentation and to reduce the impact of fragmentation is to partition the hard disk(s) in a way that separates partitions of the file system that experience many more reads than writes from the more volatile zones where files are created and deleted frequently. In Microsoft Windows, the contents of directories such as "\Program Files" or "\Windows" are modified far less frequently than they are read. The directories that contain the users' profiles are modified constantly (especially with the Temp directory and Internet Explorer cache creating thousands of files that are deleted in a few days). If files from user profiles are held on a dedicated partition (as is commonly done on UNIX systems), the defragmenter runs better since it does not need to deal with all the static files from other directories. For partitions with relatively little write activity, defragmentation performance greatly improves after the first defragmentation, since the defragmenter will need to defrag only a small number of new files in the future.


Joash

Answer 2

The answers present are very good.
Simply a defrag will move and sort folders as needed. Old or damaged folders are reduced and moved to create space for new folders.

I describe as the following:

Your bed is the Cpu of a computer - in a bedroom (the pc)
The floor at the moment is covered in books, dvds, clothes, and getting to the bed takes a long time, as you can not step on anything.

Now run a defrag

All the mess on the floor is sorted and pushed aside. Look, a new clean direct link.

The result, folders are relocated so that your system will run faster and find folders quicker.

Hope this made a defragment easier.

Note:

A defrag is very good for your system. I recommend one is carried out every month.

Answer 3

Well when you install/store things on your computer, the hd has open sectors on it of certain sizes. Like it may have a 100mb chunk here and a 1 gig chunk here. The program will be installed in the first available chunk that it will fit in. So if you had a 500mb program it would skip the 100mb chunk and goto the 1gb. When you defrag, it goes thru and re-arranges all the data from the start. so that you have 1 huge chunk at the end of the hd and not all scattered about. This way you have more space, because you might never install something that is 100mb, so thats wasted space. But if you had several 100mb spaces and you defrag, it would combine them all into usable space. Some files, like windows and what not cannot be moved tho.

Answer 4

Bill, Windows don't handle resources very well. On your hard drive, it saves new files in the first available space on the hard drive. What doesn't fit is stored in the next available space. If it still doesn't fit, then the next space, and so on. What happens is the more you use your computer the more these files get scattered into several different parts of the hard drive, causing the drive to work harder to retrieve fragmented parts of files to deliver the complete file back to you. This slows down your computer.

When you defragment, the program analyzes this fragmentation and rearranges the hard drive so that files are stored contiguously, meaning, each file is stored as one piece instead of many pieces. This makes it easier for the hard drive to deliver a file to you quickly.

Answer 5

defraging does just what it says when your PC writes to the disc the disc is spinning it cant write the files all together so they go on the disc in spots the defrag re writes the files together so that they are easier to read and take up less space.read the help file on your defrag utility for a more in depth explanation

Answer 6

The purpose of Windows Disk Defragmenter is to optimize the time it takes to read and write files to/from the disk by minimizing head travel time and maximizing the transfer rate. The used techniques include:

1. Moving all the index or directory information to one spot. Moving this spot into the center of the data, i.e. one third of the way in, so that head travel to data is halved compared to having directory information at the front.
2. Clustering files around the directory area.
3. Moving infrequently used files further from the directory area.
4. Obeying a user provided table of file descriptions to emphasize or ignore.
5. Making files contiguous so that they can be read without unnecessary seeking.

Answer 7

It take's a while to do it.But it run's better when done.It just remove's or compress'es dead file's,and thing's in your pc drive's and open's up space for other thing's to be add'ed.No big deal.

Answer 8

defraggmenting your hd means that its sorts out all the spaces between files, and i think it make more memory available, and it speeds ur pc up to

CHEERS!!