Different sizes for the same files

Discussion in 'Computer Memory and Hard Drives' started by Frantastic, Mar 7, 2019.

  1. Frantastic

    Frantastic New Member

    Messages:
    6
    I've bought a 4 terabytes external hard drive to substitute my older 1 terabyte drive.
    I've copied everything there was on it and ended up with this [see attached picture]:
    On the left it's the old drive and on the right the new one.
    How is it possible that the same files occupy way less space if on a different drive? Does it mean I lost some data somehow during the copy?
    Even weirder, if I try to check the size of the files by selecting everything and clicking on properties, it gives the original dimension, 667, on the new drive too.
    What's going on?
    Cattura differenze dimensioni.PNG
     
  2. johnb35

    johnb35 Administrator Staff Member

    Messages:
    41,667
    Did you have show hidden files and folders enabled before copying? I bet not.
     
  3. OmniDyne

    OmniDyne Active Member

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    545
    Did you ever defragment the older 1 terabyte? It's possible the 4 terabyte was able to more efficiently write the data since it was empty, therefore increasing usable space, as in saving space.
     
  4. Frantastic

    Frantastic New Member

    Messages:
    6
    I didn't, but even after enabling them and redoing the copy it's the same result. It was instant too, so there weren't many hidden files anyway.

    I doubt that would be the case, since it's only 1% fragmented. Still, I've defragmented it, and its size didn't change.

    In case it wasn't clear what I meant in the highlighted text, here's a screenshot of that.
    On the left the new drive and on the right the old one.
    The difference in number of files is because I'm using the new drive now, so it's not the case of some files not being copied over, at least according from this data.
     

    Attached Files:

    Last edited: Mar 9, 2019
  5. beers

    beers Moderator Staff Member

    Messages:
    8,345
    What allocation size did you use when formatting? If you picked a larger one than the previous drive, files that are smaller than the current/new size will consume more space as a result.

    https://www.bytesizedalex.com/get-windows-ntfs-block-size/

    False, that is an incorrect assessment.
     
    TheRealSwede likes this.
  6. OmniDyne

    OmniDyne Active Member

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    545
    In what way?
     
  7. strollin

    strollin Well-Known Member

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    1,950
    Fragmented files don't take up any more space than files that aren't fragmented.
     
  8. Frantastic

    Frantastic New Member

    Messages:
    6
    I never change that option, so I'm guessing it would be the default 4096 bytes for both of them. Besides, it's the opposite of what you said, the files apparently got somehow smaller when being copied over to the newer drive.
    I want to be sure that I haven't lost data, since I want to format this older drive for another system, but I don't want to risk losing anything.
    Also I'm sorry but I don't understand what is being said in the link you gave me, I'm not that much of a computer expert.
     
  9. beers

    beers Moderator Staff Member

    Messages:
    8,345
    The link shows you how to check.

    If you want a secondary option then rsync or use some cloning utility.
    Please explain how fragmented files occupy more space than non-fragmented ones.

    That's like saying you have a different amount of pizza after cutting one up and putting it on plates.
     
  10. OmniDyne

    OmniDyne Active Member

    Messages:
    545
    Obviously I don't understand it very well, so if you could explain to me how when a hard disk is defragmented, it often frees up multiple gigabytes of space. I've had a defragment cycle free up well over 20GB.
     
  11. johnb35

    johnb35 Administrator Staff Member

    Messages:
    41,667
    There are articles about this online. However, some seem to think that defragmenting actually deletes any old restore points which would give you a decent amount of space back depending on how much space has been allocated to system restore. Others think that yes, when files are fragmented in many different places each fragment takes up more space then what the whole file would.
    https://www.bleepingcomputer.com/fo...gmenter-has-freed-up-over-30gb-of-free-space/
    https://superuser.com/questions/307...-c-drive-increase-my-free-disk-space-by-10-gb
    https://answers.microsoft.com/en-us...ver-30gb/d85b3248-52e6-412b-ad78-c174fd3e7f7f

    So without further investigation, it would be hard to tell why the extra disk space was available after the defrag.
     
  12. Frantastic

    Frantastic New Member

    Messages:
    6
    So far I haven't noticed any missing files, so I'll assume that it's all good.
    Hopefully by formatting the original drive I won't have lost any data.
     
  13. Cromewell

    Cromewell Administrator Staff Member

    Messages:
    15,362
    This is a good visual representation of how it works.

    [​IMG]

    Basically each sector of stored data also contains the address of the next block that belongs to this file. When that is also the next physical block the drive heads can just continue reading, otherwise they need to seek. This address is there whether the file is contiguous or not, so you should not save any space by defragmenting.
     

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