Transfer data from one external HD to another?

Discussion in 'Mac Accessories' started by blairh, Mar 4, 2011.

  1. blairh macrumors 68030

    blairh

    Joined:
    Dec 11, 2007
    #1
    I'm looking to copy 2 TBs of data from one external HD (that is running out of free space) to another external HD that is 4 TBs. I only have 60 GBs free on my MBP, so for now I plan on subjecting myself to the grueling process of dumping 60 GBs at a time onto my MBP, adding it to my 4 TB drive, deleting the 60 GBs from the MBP, and repeating accordingly. :(

    Is there any way to do this faster? Thanks.
     
  2. skorpien macrumors 68020

    Joined:
    Jan 14, 2008
    #2
    Connect both drives and copy directly from one to the other?
     
  3. blairh thread starter macrumors 68030

    blairh

    Joined:
    Dec 11, 2007
    #3
    I thought about doing that, but my research online says it's very risky and prone to crashes and/or errors. I'd love to copy 2 TBs worth of data and just drag it to the new external drive, but I fear the worst. If anyone has done this with no problems, I'm all ears. I should also mention that the data I'm transferring (photos and videos) are incredibly important to me. I want to avoid messing up the original files at all costs. Even if it means the annoyance of 60 GBs at a time.
     
  4. balamw Moderator

    balamw

    Staff Member

    Joined:
    Aug 16, 2005
    Location:
    New England
    #4
    Definitely don't move files. Copy and verify.

    I usually do this in Finder or from Terminal.app and then follow up with a file comparison tool like diff or generate MD5 checksums for the files I am archiving.

    You could probably also just use a tool designed for this like ChronoSync. http://www.econtechnologies.com/pages/cs/chrono_overview.html

    B
     
  5. skorpien macrumors 68020

    Joined:
    Jan 14, 2008
    #5
    To add to balamw's post, I suggest keeping the old drive with the files intact as a backup. If the files are as important as they seem, backup should be number one priority.
     
  6. blairh thread starter macrumors 68030

    blairh

    Joined:
    Dec 11, 2007
    #6
    By "copy and verify" do you mean what I was originally planning on doing? (Drag and drop according with the 60 GBs on my MBP?) If not I'm a little lost.

    I just looked at the ChronoSync link. I'm not clear as to how it works. :confused:
     
  7. blairh thread starter macrumors 68030

    blairh

    Joined:
    Dec 11, 2007
    #7
    Absolutely agree. At first I was going to clear the data and sell the drive. But common sense tells me to just store the 2 TB drive in my closet in case I have issues with the 4 TB one. :)
     
  8. waw74 macrumors 68030

    Joined:
    May 27, 2008
    #8
    if you're comfortable with terminal look up rsync

    it copies file by file, and if you stop in the middle, and restart, it compares both directories, sees what's there, and only copies what's not there.

    the big thing that catches a lot of people is the trailing / on the source.
    so if you have a folder called source with file1, file2, file3, and file4 in it

    if you make your source "source/" it will copy files 1 to 4 to the destination.
    if you make your source "source" it will copy the folder and its contents (if you've turned on recursive)

    i normally run it with "-aP"
    • the a makes archive mode, so it copies everything including file times, and it's recursive, it basically includes a lot of options into one letter
    • the P gives it a progress indicator, otherwise you get no output till it's done.
     
  9. blairh thread starter macrumors 68030

    blairh

    Joined:
    Dec 11, 2007
    #9
    I'm definitely not comfortable with terminal. Thanks for the suggestion though.
     
  10. mstrze macrumors 68000

    Joined:
    Nov 6, 2009
    #10
    Doesn't Disk Utility allow you to copy from one drive to another?
     
  11. balamw Moderator

    balamw

    Staff Member

    Joined:
    Aug 16, 2005
    Location:
    New England
    #11
    It's a highly configurable sync solution, I suggested it over the more usual suspects:
    Carbon Copy Cloner http://www.bombich.com/ or
    SuperDuper! http://www.shirt-pocket.com/SuperDuper/SuperDuperDescription.html

    Those are designed to clone the whole drive in one go, while using ChronoSync you can break it up a bit more (e.g. folder by folder) and even schedule sync operations.

    It's basically rsync for folks who are not Terminal savvy.

    B
     
  12. RaceTripper macrumors 68030

    Joined:
    May 29, 2007
    #12
    I get really crappy performance with rsync -auP between my two FW800 drives (one a 4TB RAID 0+1, the other a 4 TB RAID 0), like only 13 MB/s. I get about 60 MB/s with a Finder copy, more than 4 times faster.
     

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