Time machine causing external HD problems?

Discussion in 'Mac Apps and Mac App Store' started by chapmac, Feb 17, 2010.

  1. chapmac macrumors member

    Joined:
    Dec 30, 2007
    Location:
    UK
    #1
    Hi - I hope someone out there might be able to help. I've searched the web and this website and can't find a solution to my issue...details below.

    I have two Macs both of which are running snow Leopard. To back these up I use time machine connected to a single external USB hard drive. I simply connect the drive to the machine I want to backup once a week or so and it will back up.

    For a while, everything worked just fine, I even needed to recover files from it and did so successfully. Occasionally one or other of the Macs would take a while to recognise the drive but normally it would be OK. Gradually the problem got worse until neither machine would recognise the backup drive. I mean nothing - not only would it not mount on either machine but wasn't recognised in disk utility either. As the disk was about 3 years old I figured it was probably the drive on the way out so bought a new Seagate drive to replace it.

    Again, it worked fine to start with, but now after only about two months exactly the same problem has occurred and now the new drive is not recognised at all either. Now it could be that I'm just unlucky and have two dead hard drives but I don't think so, especially as the new drive has had very little use.

    I'm guessing that somehow using the backup drive with more than one machine has caused the problem but I don't know how to fix it. I have tried everything my (limited) knowledge will allow.

    - Repairing disk permissions
    - Allow OSX time to find the drive (I've left it for hours but to no avail)
    - Booting the machine up with the usb drive already plugged in

    As the drives are not recognised by either machine at all, I don't know what else to do. If I could see the drives I'd be happy to format them both and use one on each machine if this would fix the problem but I can't even do that.

    Does anyone have any suggestions or can shed some light on this?

    Thanks in advance.

    Dom.
     
  2. spinnerlys Guest

    spinnerlys

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    #2
  3. chapmac thread starter macrumors member

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    Dec 30, 2007
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    UK
    #3
    Thanks for the swift reply.

    Yes you are correct. The both the drives were simply OSX formatted in one partition. Looking at the files on the disk itself (when I could!) time machine simply created a directory for each of the two Macs using the name of the machine and then backed up the machine into the relevant directory.

    Never heard of a SMC reset so will try that the next time I am at the machine and can try it.
     
  4. spinnerlys Guest

    spinnerlys

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    #4
    Ah, okay. Didn't think Mac OS X could do that, but it's nice to see it can.

    I hope the SMC reset helps.
     
  5. drummerlondonw3 macrumors 6502a

    drummerlondonw3

    Joined:
    Feb 10, 2008
    Location:
    London
    #5
    as this problem is happening on both drives it would seem more likely to be a software issue.

    Go with the SMC reset and see how that gets you

    I would imagine its something to do with an increasing file directory? i.e. as the time machine back ups increase they are some how blocking the drive?

    I currently back-up 3 macs onto a 2TB time capsule drive (self-upgrade) and it all works flawlessly, well most of the time.

    Do you have the drive attached to both computers? Could you explain how the drive is set up in relation to the computer?

    Last question (for now) - have you tried simply placing 2 partitions on the drive?
     
  6. chapmac thread starter macrumors member

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    Dec 30, 2007
    Location:
    UK
    #6
    drummerlondonw3 thanks for your reply.

    It's a low tech approach to backing up. One machine is a MB the other is an MBP, so its just a case of plonking the machine on the desk next to the backup drive and plugging it into to a USB port when I want to do a backup, normally once a week.

    Not sure about the file directory, but I do know that when the original HD was filled time machine quite happily removed the oldest backups to make space.
    Can't speak for the second drive as I didn't fill it before the problem occurred.

    I didn't try putting 2 partitions on a drive, and of course I can't now as I can't see the drive!
     
  7. chapmac thread starter macrumors member

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    #7
    ...and no luck with the SMC reset I'm afraid......
     
  8. Jackyl macrumors newbie

    Joined:
    Dec 17, 2008
    #8
    If it were me I would do a re-install using the Snow Leopard Install disk. If anything is off this install will allow any system software to install to it's original state, and will not alter your other software.
     

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