Disk Defragmentation ?

[rvp11]

Hi, I wanted to know what disk defragmentation is and how and why is it helpful/harmful.
Also, -for people who have done it- are there any risks that while defragmenting your hdd, something can go terribly wrong and your hdd is gone forever? from what i understand when u delete a file from windows, the system doesn't exactly erase the file on your hard disk, so u can using some special programs retrieve or edit that file. This 'deleted' disk space and the file u deleted remains on your hard disk until another file replaces it or something of that sort. OR is you defragment your hard disk then all the files that the system renders deleted, are in turn replased by other files, so that the 'Gap' of this deleted file is utilized and overridden.At least that's what i understood by reading a few snippets here and there. Is all this correct? Another part of my question is that for example if i have a 300 gb hdd, which is divided into 4 partitions, c,d,f,e, if i defragment my hdd, will any of my deleted data in lets say drive c be overridden by data in drive e?

Appreciate your assistance and advise.

[OlyComputers]

You can't defragment an entire drive, it's by partition. So you wont have to worry about defragmenting one drive effecting the other.

As far as what disk defragmenting is, think of it like this:

When you have a pizza, you take pieces here and there leaving gaps, but when you want to put it away you move the pieces together so it's more space-efficient to wrap. It's a dumb analogy, but I'd bet you get the point.

The benefit of it is that keeping all the data in one large, contiguous, piece makes it easier and more efficient to access. But it will make any data recovery unlikely sine it moves data around.

As far as deleting documents, when you erase a file on your computer it doesn't erase it the way you would erase something on paper. It simply removes the file systems references to it, making it unavailable and free to be over-written. Data recovery software will check empty space on the drive for usable data that is not referenced by the file system, but generally you need to do it right away because any use of the drive will risk permanent loss of the files (by over-righting the unmarked sectors where the files were)

Hope this helped and if you have any more questions feel free to ask.

[A_member]

When you have a pizza, you take pieces here and there leaving gaps, but when you want to put it away you move the pieces together so it's more space-efficient to wrap. It's a dumb analogy, but I'd bet you get the point.

that's just about right, and im not aware of any inefficiencies it may cause but to go with that it doesnt provide much of a benefit as well. maybe slight improvement in performance.

[tigerbright]

Hi - can be good for 20% improvement in hard disk drive intensive tasks such as full system maintenance scans

basically relocates all the files to the fastest part of the drive.

can be a 30% difference in raw data transfer rate between the fastest and slowest location on the disk

I suggest install a utility called HD Tune
(freeware after clicking on the downloads button, left hand side)
and run their benchmark
which will display in charted form how quick the disk is transferring data thoughout the whole disk surface
http://www.hdtune.com/

The start is the outside tracks and the end is the inner tracks.

This is sustained data transfers - one aspect of disk performance.

VISTA automatically defragments the disk drive.

Hope this helps

[joshuah]

Hi, I wanted to know what disk defragmentation is and how and why is it helpful/harmful.
Also, -for people who have done it- are there any risks that while defragmenting your hdd, something can go terribly wrong and your hdd is gone forever? from what i understand when u delete a file from windows, the system doesn't exactly erase the file on your hard disk, so u can using some special programs retrieve or edit that file. This 'deleted' disk space and the file u deleted remains on your hard disk until another file replaces it or something of that sort. OR is you defragment your hard disk then all the files that the system renders deleted, are in turn replased by other files, so that the 'Gap' of this deleted file is utilized and overridden.At least that's what i understood by reading a few snippets here and there. Is all this correct? Another part of my question is that for example if i have a 300 gb hdd, which is divided into 4 partitions, c,d,f,e, if i defragment my hdd, will any of my deleted data in lets say drive c be overridden by data in drive e?

Appreciate your assistance and advise.

Defragging puts fragmented files back together sequentially to speed up data access. Its a good idea to defrag your drives regularly and keep fragmentation under control. MS has an inbuilt defragger that you can use (for which you need to have about 15% free space) or opt for a third party tool( I use Diskeeper, set to automatic mode). There isnt anything 'risky', but its good to make sure there wont be a power cut while the defrag is in progress.
You can select the partitions to be defragged and the defragger will defrag it.

[jbennet]

ms defrag is slow

i use auslogics defrag

virtually no risk unless your hard drive is on its way out anyway

VISTA automatically defragments the disk drive.

So does xp. Auto-defrag is crap though.

and + 1 for olycomputers explaination

basically relocates all the files to the fastest part of the drive.

not really. There is no fastest bit, what is fastest is when all the data that relates to eachother is near to eachother, that way to load a single thing, it doesnt have to look in 10 different places whichg are miles apart from eachother. This reduced seek time will make your HDD last longer and it is faster.