How does defragging work?

Hi

Various software all tend to employ what the makers think are the best options for defrag, the free defraggers tend to only use space defrag methods which just removed space from inbetween files, thus compacting the HD used area, while this works it may not be the best method as other defraggers use defrag methods such as Access, Modified and Name.

With FAT16/32 file format thes tend to fragment a fair bit, however NTFS by its very design doesnt fragment alot as what it does is add small gaps/spaces betwwen the files so to allow for updates to those files, so when they expand they are not becoming fragmented into two areas, works quite well but NTFS still fragments but not as much as FAT, which is why NTFS doesnt need alot of defragging maybe in my experience, once or twice a year, depending of fragmentation %, if under 10% I wouldnt bother at all.

Last time I manually did a defrag of my main C: Drive was back in August 08, and from that time till now, with many installs and uninstalled plus updates to Windows the fragmentation of a 140GB HD in Raid0 is only 0.07% with 542 files listed as fragmented, so not worth defragging again, why I mentioned manual defrag is in that I use O&O Defrag 11 wich has an auto silent mode defrag which kicks in now and again and does a minute or so cleanup when PC is idle.


My normal node of defrag is Access, which means, it will order the files as per the amount of times they are accessed so common files will be at the fastest part of the drive, but this method is long and can take hours to complete.

I personally like and use O&O Defrag 11 Pro, but there are other products available and trials and freeware versions of the best known ones are listed in the Majorgeeks link I posted below, JKDefag, Auslogic Disk Defrag and Defraggler are good free ones that likely just use the Space method of defragging.


Some info for you on defragging.....

http://en.wikipedia.org/wiki/Defragmentation
http://www.oo-software.com/smb/en/support/faq/oodefrag/index.html#toc_23 (O&O modes of defrag)
http://majorgeeks.com/download.php?id=8 (drive utilities from Majorgeeks, includes many paid and free Defraggers)
http://www.microsoft.com/windowsxp/using/setup/tips/defrag.mspx (setup XP to auto defrag using its inbuilt defragger)
http://windowshelp.microsoft.com/Windows/en-us/help/d19994eb-6648-464e-a0d2-072c920f18a61033.mspx (same schedule in Vista)