What is involved with reformatting a HD?

Discussion in 'Mac Apps and Mac App Store' started by MikeTheVike, Aug 13, 2015.

  1. MikeTheVike macrumors regular

    Aug 8, 2009
    My Macbook Pro Mid-2012 has been running horribly slow for a while now. Constant beachballs and loading and switching apps is really slow. I got on Disk Utility and did the "Repair Disk Permissions". I also clicked on "Repair Disk". It asked me to restart my computer and hold Command-R to open Disk Utility and run the repair disk from there. I did that and it ran for a while and then said it couldn't complete the repair and to backup all files and reformat. This is a work computer, so I have to make sure I do things carefully. I do have a time machine backup, but I can't find in the Time Machine settings whether it's backing up just files or system files as well. If I went through the reformat process, what steps can I expect to get back up and running again? Will all my computer and software settings carry over? Will I have to type in serial numbers again for all my software? Anything else? Thanks for any info!
  2. keysofanxiety macrumors G3


    Nov 23, 2011
    If I were you I'd check the hard-drive SMART data to make sure it's corrupted -- if it's corrupted then wiping/reinstalling won't do any good for a hardware failure. You can download SMART Utility here, anything other than Passed means you need to replace the drive.

    And you can restore Time Machine backup directly to replacement HDD.

    Please quote this to let me know the news about the HDD and I'll advise further about what to do in either event.
  3. MikeTheVike thread starter macrumors regular

    Aug 8, 2009
    keysofanxiety, looks like it PASSED ok.
  4. keysofanxiety, Aug 13, 2015
    Last edited: Aug 13, 2015

    keysofanxiety macrumors G3


    Nov 23, 2011
    OK, that's great to hear.

    By default, Time Machine backs up the whole hard-drive (just OS X though, no Windows partitions), so unless you've manually changed any settings it should all still be there.

    My concern is that it's difficult to say when the volume corruptions occured, so restoring from Time Machine may well just restore the problems. Furthermore, with such heavy volume corruptions that can't be repaired, even an earlier TM image may have niggling background problems that will compound over time. As such I'd recommend wiping the internal HDD completely, installing a fresh copy of the OS, and perhaps use Migration Assistant (or manually drag and drop) to then restore all your data.

    Hold Cmd+R on startup, and open Disk Utility. From there, click the bottom Macintosh HD partition, click the Erase tab, and erase as Mac OS Extended (Journaled). Then when that's formatted, close Disk Utility, and click 'Reinstall OS X'. Select the newly-formatted partition. You may need to sign in with your Apple ID.

    It will then download the operating system components and install it from there. If you have an Ethernet cable or a fast Internet connection, that will definitely benefit it. If you're on ASDL you might want to pour yourself a hefty whisky and pop on the telly.

    It'll all be installed from there. Migration Assistant is nice and easy to use, though there are a few users on this forum who recommend against it and prefer to use other apps. At any rate, you've got everything backed up on Time Machine. :)

    Let me know if you have any problems or further queries!
  5. Fishrrman macrumors G5


    Feb 20, 2009
    OP wrote:
    "My Macbook Pro Mid-2012 has been running horribly slow for a while now"

    Put an SSD in it.
    It -WILL- run much MUCH better.

    The job is easy IF you have the RIGHT TOOLS.
    I believe you'll need a Phillips #00 driver and a TORX T-6 driver.
    Easily available from many places.
    Check the drive replacement guide at ifixit.com

    I'd suggest a Crucial SSD, either 240gb or 480gb. You can find the 240gb for around $100 or less, 480gb for $200 or less.

    I also suggest you pick up an external USB enclosure.
    PREP and TEST the drive first.

    The old drive may still become usable for a backup after you swap it out and re-initialize it (the slowdowns may be software-related instead of hardware-related).
  6. MikeTheVike thread starter macrumors regular

    Aug 8, 2009
    If the data is corrupt, more than likely it is corrupt on any backup version I have as well. Not goign to lie, scary thought reformatting and starting again, even with the backup. Sounds very time-consuming for a work computer I have to use everyday. I'll definitely have to do something soon though. Thanks for the info.
  7. MikeTheVike thread starter macrumors regular

    Aug 8, 2009
    I would probably want a 1TB drive as that is what I have now and it is 75% full. It would be awesome to have a SSD drive. nervous about opening up my work computer though, haha. Thanks for the info.

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