Forum Question: How Do I Backup a USB Data Ext. HDD To Another USB Ext. HDD

I have all my data files on a 1Tb external hard drive and as a safety precaution I would like to either use Time Machine or another Utility to automatiCally back them up to a second external hard drive.
Don Swearingin

Comments: 6 Responses to “How Do I Backup a USB Data Ext. HDD To Another USB Ext. HDD”

    10/29/11 @ 7:13 pm

    If you have the drive connected to your Mac, it should be backing up to Time Machine as well as your internal drive, as long as you haven’t specifically excluded it.
    But you can also clone the drive from time-to-time to a second, backup drive using SuperDuper or Carbon Copy Cloner.

    10/29/11 @ 10:07 pm

    I’m not real familiar with Time Machine but when I try to use Time Machine on any of my three computers it only gives me the option of backing up my internal hard drive and that drive only has the OS X 10.6.8 and Apps on it. I want to back up my external portable drive that has all my data on it without having to clone it every month. The cloning process is what I have been using in the past but today I almost had a heart attack when for some odd reason my external drive was not recognized by any of my computers and I had to reformat it and I lost one whole months very important work. I want something that will backup my external hard drive automatically to another external hard drive while I am using my computer. I cannot use an online backup service because I use my computer for prolonged periods in areas of Mexico that don’t have Wi-Fi, telephone or Ethernet accessibility.

      10/29/11 @ 10:19 pm

      Time Machine will backup external drives. Are you sure it isn’t? You said it “only gives me the option of backing up my internal” — but it never “gives you the option” — it just works. So where are you seeing proof that it isn’t?
      If you have the external drive and the TM drive plugged in during normal use, it should be doing so automatically. What happens if you try to use Time Machine to recover a file from the external. That should show you it is working or not.
      I have heard in the past that sometimes adding the external drive to the exclusions list, and then removing it from the exclusions list can start it backing up the drive if it isn’t already.

    11/2/11 @ 2:16 pm

    I’m thinking that I’m not communicating what I want to do. I have two external hard drives. The first one has all my data files on it. I want to back it up to the other external hard drive. When I open Time Machine it gives me the option of which hard drive that I want to use as my time machine. I have selected the second external hard drive as the destination drive but then I can’t figure out how to select my first external hard drive as the source drive to be backed up. The Time Machine wants to use the second external hard drive to back up my system hard drive and that is not (NOT) what I want to do. I already have an exact clone of my system hard drive.

      11/2/11 @ 2:20 pm

      You select the drive to use as your Time Machine backup. TM should them backup ALL of the drives you are using. So you would get a backup of both your internal and your first external drive too.

    11/2/11 @ 3:06 pm

    Thanks, that answers my question. It won’t work for me since my destination drive doesn’t have enough space for both the internal systems drive and the external data drive.
    Just the same, I really do thank you very much for your help.

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