Copied folder, twice the size.

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Copied folder, twice the size.

I'm trying to copy a folder from one internal drive to another. It's about 170GB of video files, but ends up being over 240GB when it's copied. I went through the subfolders, some seem fine while others are twice the size. For instance a subfolder with 6GB of MP4 files, ends up being 13GB. Any ideas on why that would be?

I'm also getting the dreaded error -36 when copying to some of my external drive. Three seem to work fine, while two don't. I would think that the drives might be bad, but one was old and one was new. It was like they had infected each other.

Thanks!

MacBook Pro, Mac OS X (10.6.2)

Posted on Jun 23, 2010 8:42 AM

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Answer 1

Jun 23, 2010 2:13 PM in response to rpfive

rpfive wrote:
I'm trying to copy a folder from one internal drive to another. It's about 170GB of video files, but ends up being over 240GB when it's copied. I went through the subfolders, some seem fine while others are twice the size. For instance a subfolder with 6GB of MP4 files, ends up being 13GB.

I may be way off base, but if the destination drive is bigger than the source drive, what you're seeing may be explained by the size of the "allocation unit" of the drives. There is a minimum amount of disk space that even the smallest file will occupy. On my 125 GB boot volume that minimum size is 4 KB. Do a Finder "Get Info" of one of the files on the source drive and the same file on the destination drive. Compare the "Size" values of each file (not the values in parentheses).

I'm also getting the dreaded error -36 when copying to some of my external drive.

How are those external drives formatted?

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Answer 2

rpfive Author

Level 1

25 points

Jun 25, 2010 7:14 AM in response to rpfive

Thanks for your reply William.

As far as the folder size goes, I had to blow away the original as I had to make drive space. I had to take the chance that if the folder copies at twice the size, then all the media is sure to be there. Hopefully it's not corrupt. I have a backup on another drive somewhere anyways. Also, both drive where the same size, although the drive that was being copied to had far more available space.

As far as the external drives that aren't working, they're formatted as Mac OS Extended (Journaled), and the partition map scheme is "Apple Partition Map". The internals, which seem to be working fine, are using the "GUID Partition Table". Perhaps that's the problem, although it seems the two externals that are still functioning (G-Raid 500GB) is also using the "Apple Partition Map". I'm at a loss. Perhaps I've just had two drives go down at the same time. Just a coincidence.

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Answer 3

Jun 25, 2010 8:34 AM in response to rpfive

rpfive wrote:
As far as the external drives that aren't working, they're formatted as Mac OS Extended (Journaled), and the partition map scheme is "Apple Partition Map". The internals, which seem to be working fine, are using the "GUID Partition Table".

I don't claim to have a complete understanding of the technical details of your situation, but I wouldn't expect the partition map scheme to have much if any effect on the storage efficiency of a drive. So that leaves your situation unresolved.

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