Why is Carbon Copy Cloner taking forever

Discussion in 'Mac Apps and Mac App Store' started by Razeus, Nov 7, 2011.

  1. Razeus macrumors 603

    Jul 11, 2008
    I've backing up (finally:eek:) my 2TB external hard drive that contains all my photography, iTunes, iTunes Lossless, books and Video files. It's about 1.2TB worth of data. I started the backup process on a fresh external around 9:30pm last night and today, around 2pm, it's only 50% complete.

    What's taking so long? I could have drag and drop faster than this. I'm not running a checksum or anything like that. I believe CCC is setup to only backup files that have changed after this initial first backup. What is it doing?

    FYI: My main external drive "Media HD" is on FW800 and my backup drive "Archive HD" is a USB 2.0. These are simply "media content" files, no OS X or system files on my internal drive inside my iMac.
  2. bmcgonag macrumors 65816


    Mar 20, 2007
    I've had success with first fixing permissions via the Disk Utility, then running CCC. However 1.2 TB is a huge amount of data over USB 2.0. It could just take a long time. The difference is that with CCC it does what's called RSync.

    RSync also handles backing up metadata, permissions info, etc. So, it's different from just copying or moving a file with drag and drop.
  3. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    What I see different about what you are doing is using CCC to go from one external drive to another with the computer in the middle. So you have the firewire bottleneck on one end and the USB2 bottleneck on the other. I wonder if this combined is what is making it so slow?

    Are both drives formatted to HFS+? Fat32 formatted drives will work in OS X but cause very slow performance.
  4. Razeus thread starter macrumors 603

    Jul 11, 2008
    Yes HFS+ formatted. I have no need for Windows formats.

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