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Folks,
I've copied a folder(size: 10.7GB) to external HD, and it's occupying 154GB on external disk.

yes, the folder has a lot of small files in it. but ..

Surprisingly, the same folder occupy 10.8GB on internal HD. and that drive is not compressed.

I defragmented external HD, problem still unresolved.
* allocation unit size is default(4096B) on both the disks. both are NTFS

Plz, help me, explain me... :-(

Comments
  • 7
    Have you tried reformatting the drive? It seems like there are actually huge blocks used
  • 1
    I think there might be compression enabled on folder level even if the whole drive isn't compressed. Click the "Advanced... " button and see.
  • 0
    @kamen checked, nope it isn't
  • 6
    Seems like a ridiculous discrepancy. But here’s some thoughts:

    • Sparse files (10gb filesize but only has 4kb of actual data; rest are unwritten zeros)
    • File system overhead (block size: 4k, file contents: 4 bytes)
    • Security descriptors (?)
    • Copied over an (uncounted) mount point or symlinks?
    • Transparent compression on the source drive?

    I’m not sure what could account for the discrepancy.
  • 0
    what filesystem is the partition on the external drive?
  • 0
    Compress the folder, check its size before copying, and try again
  • 0
    @Root ntfs does not support sparse files
  • 0
    @iiii Are you positive?
    I’m tired and can’t remember, but I remember working with them on Win7.

    Maybe it was just research as it was around a pretty odd problem. idk. It’s nearly 4am and I’m too tired to think.
  • 1
    @Root totally positive. The only similar thing ntfs has is compression. compressed file can sort of behave like a sparse file.
  • 0
  • 4
    Have you tried chkdsk /F

    Could be a corruption in the MFT (Master file table)
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