How calculate post-defragmentation freed space before it

arttss

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I need to free some enough space on system disk. I checked by native windows defragmentator and it says that it needed to be defragmented. The Defragler utility shows 57% files fragmentation on disk C: (and about 40% on two other partitions) but it has no indication how much space could be freed. If there is about 200 mb on 10 gb system partition how much can I count on in case of such defragmentation? What is more effective - windows or defragler defragmentation? I should also not there is some 0.5 gb of failed VStudio re- installation files that I could not find and delete if it is possible in the whole. I should also note that disk C: has some 8 kb bad sectors that was repaired by hd regenerator but probably they are replaced by other spared sectors so I am not aware how such changed references could be impacted by defragmentation? Here I should note that I entered deficient LBA in WinHex-Go Sector and eventually got some item (file alike item) with name bad_sector with 8 kb label, but to view (right click) it needs superior license, to view in notepad -- it shows wild unreadable charactersd, and if open -- there are 2 columns -- hex and ascii values (with some reference to registry in last case).

 

RolandJS

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As a layman, I can only give you a layman's answer: Picture a room with 100 volumes of a reference set all over the place, defragging would simply put all the books from 1 through 100 back in order on the shelf. You will not gain much byte-space from defragging. You have to begin removing programs you no longer need, and archive data you no longer need onto external media.
 
You will not recover space of any significance. The only space to be gained is that when parts of a file are in sectors that are partially full, the reorganization may allow some of them to be rewritten to full sectors. So it may shrink slightly but only slightly.

What messages about "free space" generally refers to is that you need free space in order to accomplish defragmentation. large files are the ones that generally result in the most degragmentation especially when they change size. So if you need to defragment a 2 GB file....it needs up to 2 GB of space to hold it temporarily, 2 GB for where it now is and 2 GB to put it somewhere. That can be cut down somewhat doing it sector by sector but you get the idea. It is recommended that you never let a storage volume get less than a 15% free condition.
 

arttss

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I do understand taht theoretically it should not free space -- but just once I did defrag about half pf year and it freed the some hidden files, indeed now microsoft office needs some account preferences, so probably just full OS reinstall would help.
So I would hope that temporal files I used during partial vS 2010 would be deleted. Indeed what about bad sectors -- what would happens with previous references? And taht bad sectors?
 

arttss

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I have just one serious question: do lba adress of bad block is saved during reallocation/repair. If not repaired the bad blocks stops defragmentation I have read? Indeed my bad blocks were repaired by hd regenerator I see 2 reallocation event but 0 reallocation sectors. Should it mean that windows would not recognize such repair and I would not able to defrag disk C? Should it stop during running or analysing the defragmentation?