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Naturally by defragmenting there should be increase in free space but when I defragmented my free space decreased by 10 GB nearly why it happened? Any one over there can help me?

Dave
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sudarshan reddy
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    `Naturally by defragmenting there should be increase in free space` - er, no! Very simply: defragmentation reduces the amount of fragmentation by physically moving content on the disk so each piece of a single file are closer together and ideally contiguously. – Dave Feb 20 '15 at 09:35
  • Do you have more than 1 hard drive/partition? – Dave Feb 20 '15 at 09:40
  • Only if you use compression I'd expect the free space to change. – Dan Feb 20 '15 at 10:11
  • Well, Defragmentation doesnt affect Memory space usually. It arranges the data scattered in you HDD orderly , such that all data are ordered compact. Which says No memory Loss or no Gain. – Aravind S Feb 20 '15 at 12:38
  • you see a grow of volume shadow copies. Disable system restore before doing a defrag – magicandre1981 Feb 20 '15 at 18:14

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Defragmenting shouldn't effect free space that way - it simply moves files around on the disk in attempt that full files appear sequentially on the disk rather than scattered in fragments all over the disk.

Chances are, you're probably looking at the creation of temporary files, system restore points or volume shadow copies created as the result of defragmenting.

Flyk
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    There may be increase in free space, actually. As process consolidates files, there is better usage of storage space on the hard drive - files are being written continuously throughout the clusters, instead of being stored piecemeal on the whole drive. Admittedly, this would not be much (megabytes maybe)... – AcePL Feb 20 '15 at 09:46
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    Sure, but that isn't the purpose of the defragmentation tool. I didn't say "shouldn't" :) – Flyk Feb 20 '15 at 09:47
  • @AcePL, source please? – Dave Feb 20 '15 at 09:50
  • Aha! Trying to word-trap? ;) I've seen original version of answer. Now is much better. I'd recommend "Shouldn't effect free space that way"... – AcePL Feb 20 '15 at 09:50
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    No source, just knowledge how HDDs work. I know it's counterintuitive, but can happen. For instance - mentioned huge number of small files, or heavily fragmented large files sometimes cause MFT to spill over to the workspace of HDD. If you defragment, it gets removed. Also there are reverse effects of causes mentioned by Flyk ;) – AcePL Feb 20 '15 at 10:02
  • There's a great answer [here](http://superuser.com/a/307810/288397) which covers how de-fragmentation will most probably affect free space in some form. – Hayko Koryun Feb 20 '15 at 12:40