Reads empty blocks during free space defrag

[rodalsa1]

I was doing several consequtive free space defrags and on the last one I noticed that during the drive map update a white (empty) block would turn yellow (reading this one) during the drive map update.  I then focused on this strange event and saw many more identical events.

 

Does anyone understand this well enough to explain it to me.  It appears totally illogical from here.  The best that I can do is to suggest three possibilities.  1)  The new read blocks are randomly chosen (low probability).  2)  The blocks are not really empty but are displayed as such.  3) It is a (oh horrors) a <><>BUG<><>! Stomp. Stomp. Stomp.

 

Rod

 

For me to believe is insufficient for you to know.  - rodalsa

[eL_PuSHeR]

For me free space defrag is bugged. It doesn't work as it should. It tends to create further fragmentation. This is one of a list of long standing bugs that I would like to see fixed. A "quick fill gaps" feature would be real handy. Also, the annoying "access floppy drive" whenever you click on a drive is another long standing bug.

[rodalsa1]

UPDATE:

 

While studying another aspect of Defraggler's drive map, I noticed that white blocks (Empties) reported both empty and files when floating the cursor over different blocks.  I have seen up to 63 files reported in a white block.  There could be more.  Clicking on the 63 file block produce both File Folder and Unknown File types all of which contained 0 KB and were identified as containing 1 fragment and a filename [Folder Entry].

 

So it 'appears' that my possibility #2 is the correct one.  The white blocks are not empty of 'Files'.  For the blocks that I observed (approximately 75) some contained actual Filenames as opposed to [Folder Entry] while 100% of them were File Folders having 0 KB size.  This leads me to speculate that the color white is assigned to blocks that have 0 KB.

 

Beyond that I navigated, using explorer, to the folder indicated for several of these 0 KB, [Folder Entry], File Folder, "Highlighted" Paths that were presented and found within that path's final folder a 3 KB file having extension *.wxl.  My exclusion list was empty.

 

So much for white blocks being empty.  Now 3 KB = 0 KB.  My high school math teacher is turning over in her grave -- muttering "What is this world coming to?"

 

Someone needs to edit/add a subroutine!

 

Rod

[Andavari]

Now 3 KB = 0 KB.

 

If only that were true, I'd have infinite hard disk space and we'd all be raving about the newest 1 MB SSD drive we bought for $1 USD. 

[Derek891]

Hello Rod and welcome. I think the drive map is misleading to a lot of users. Each block on the map does not correspond to one sector on the drive. If that were the case, the drive map would have to display nearly 250 million blocks (at 4096 bits/sector) for a 1TB hard drive. (My right index finger hurts just thinking about scrolling that far!) The drive map must fit in a very limited space, so each block represents a very large number of sectors. Some have data, and some do not, so I imagine there's a threshold value involved, let's call it x. If a block has >x bits of data, it is marked as occupied, and a block having <x is marked as empty, even though some individual sectors within the block do contain data.  

[rodalsa1]

Right on Derek891.  What I have difficulty with is why any arbitrary threshold other than zero.  From where I view this there are only two changes involved.  One is to change a block color.  The other is to change a  zero in the file list to "3 KB".  What is the deep dark secret that lies in the bowels of computer hardware/software technology that mandates a threshold larger than zero?

 

I mentioned studying another aspect of the Drive Map in an earlier post.  While not pertinent to this thread, I will mention its subject and post more about it in a thread that I will name, "How many Blocks are on my screen?".  There -- both the subject and the name in one question.