Identical backup can be very different..

Discussion in 'Mac Accessories' started by melaitaliana, Jan 17, 2012.

  1. melaitaliana macrumors newbie

    Joined:
    Oct 31, 2011
    #1
    Hello,
    I backup all content from time capsule to hard drive. Perfect Identical back up, same files, just copied. 10 hours needed but no errors.

    - Time Capsule shows 973 GB of space employed and 25,04 GB of space free.
    - Toshiba shows 998 GB of space employed and 1,98 GB of space free.

    25 GB of difference!? Too much. How is it posible?

    Details :

    - Info screen-shot

    - Lion version 10.7.2

    - Disk Toshiba 1TB Model E05A100PBU3XS (formatted Exfat)
    http://www.bhphotovi...o_3_0_Plus.html

    - Time Capsule 802.11n (1st generation) 1TB

    Thank you in advance for helping.
    Grazie mille in anticipo per tutto il vostro contributo
     
  2. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #2
    If you just dragged a backup via Finder, it might not have copied all data. Better use CarbonCopyCloner for cloning TC to another HDD.
    Btw, 1,98 GB free capacity is not really good, it is advised to have at least 10 percent of the HDD's full capacity free (100 GB out of 1 TB).
     
  3. melaitaliana, Jan 18, 2012
    Last edited: Jan 18, 2012

    melaitaliana thread starter macrumors newbie

    Joined:
    Oct 31, 2011
    #3
    Thank you. I copied with Carbon, Much better than before, but continue to not understand why this 2 disk are not identical.
    Time Capsule:973.013.221.376 byte (973,01 GB su disco) - 25,04 GB free
    Toshiba: 984.026.054.656 byte (984,03 GB su disco) - 16,15 GB free

    Here it is all info, as you can see, folders are identical but the total at the end is difference. Example for folder named "Time Capsule" the bigger folder:

    Folder name: "Time Capsule" - on both disks the dimension of this folder is the same 931.017.075.505 byte but dimension on disk and number of files on disk change! How is it posible?
    Time Capsule disk: (931,24 GB su disco) for 102.955 elements
    Toshiba disk: (939,31 GB su disco) for 102.969 elements
    Dimension of Folder named "Time Capsule" on Time Capsule drive and Toshiba drive: 931.017.075.505 byte (identical).

    - Info drives before and after copy

    - Carbon Copy says OK

    - Comparing folders
    (Note: Dimension total byte are always the same but GB on the disk are always more on Toshiba and number of elements are different):

    Total byte, Number of elements and GB on disk of folders on Time Capsule drive:
    - Colombia Musica: 6.893.763.121 byte (6,9 GB on disk) for 1.845 elements
    - Materiale Didattico: 1.379.154.644 byte (1,38 GB on disk) for 268 elements
    - Rosetta Stone: 7.573.845.325 byte (7,58 GB on disk) for 666 elements
    - Simon: 25.717.732.831 byte (25,73 GB on disk) for 5.474 elements
    - Time Capsule: 931.017.075.505 byte (931,24 GB on disk) for 102.955 elements

    Total byte, Number of elements and GB on disk of folders on Toshiba drive:
    - Colombia Musica: 6.893.763.121 byte (7,02 GB on disk) for 1.849 elements
    - Materiale Didattico: 1.379.154.644 byte (1,4 GB on disk) for 268 elements
    - Rosetta Stone: 7.573.845.325 byte (7,62 GB on disk) for 666 elements
    - Simon: 25.717.732.831 byte (26,08 GB on disk) for 5.470 elements
    - Time Capsule: 931.017.100.081 byte (939,31 GB on disk) for 102.969 elements

    Curious on Simon folder there are less elements on Toshiba 5470<5474 but also in this case Gb are more on Toshiba 26,08>25,73

    --------------------------------

    I hope these informations can help you to help me, thanks in advance.
     
  4. Jynto macrumors 6502

    Jynto

    Joined:
    Jan 16, 2012
    Location:
    Nottingham, UK
    #4
    Yes, my cloned drive is smaller than my actual boot drive. That's to be expected. I believe there are certain files that are created on a drive when the operating system boots off it, which take up a lot of space, including the sleep image (which has a size equivalent to all the RAM you have).
     
  5. CylonGlitch macrumors 68030

    CylonGlitch

    Joined:
    Jul 7, 2009
    Location:
    SoCal
    #5
    Look at the format of each drive; if they are not setup identically then that can account for much of the differences. Often cluster size is to blame.
     
  6. MisterMe macrumors G4

    MisterMe

    Joined:
    Jul 17, 2002
    Location:
    USA
    #6
    ExFAT and HFS+ are two completely different file systems. It is expected that an ExFAT volume and an HFS+ volume would have different capacity requirements for the same files.

    BTW, ExFAT is useful for exchanging files between a Mac and a Windows PC. However, there is no good reason to backup Mac files to an Ex-FAT volume.
     

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