5 Replies Latest reply: Dec 6, 2012 11:07 AM by Eric Root
fahmi5389 Level 1 Level 1 (0 points)

I used to back up my mac on an external hdd when i was on lion, but after updating to mountain lion my back up goes so show, its now backing up about 500kbps on usb!!! It used to work fine when i was on lion, i was using the sade hdd on lion, it was fine then. Is this a problem with mountain lion or hardware problem. By the way i aslo use another partition of the hdd as an externàl hdd and even that works completely fine. The settings of the hdd is also correct i think cuz it worked on lion

MacBook Pro (13-inch, Mid 2012), OS X Mountain Lion
  • 1. Re: Why is time mechine so slow on mountain lion
    dwb Level 7 Level 7 (20,210 points)

    How long have you had Mountain Lion installed? How many backups has TM made with ML? How much space is left on your external drive?


    I ask these questions because I found that for about a week, TimeMachine was running slower than it had under Lion. It seemed that the preparing backup stage took a very long time and then the first few megabytes were slow. But the backups are going much faster now - as fast as Lion was - though the preparing stage does still seem to take longer.


    Another thing I noticed on my notebook which has a smallish TimeMachine drive is that the thinning process (erasing when more space is needed) does seem to take longer which results in a slightly slower backup. This was true of Lion too - but I think a ML backup that requires thinning does take longer than one with Lion.

  • 2. Re: Why is time mechine so slow on mountain lion
    fahmi5389 Level 1 Level 1 (0 points)

    Iv had it installed for about a week, and i even formated the drive so i have 400gb free, my backup is only 100 gb. And my preparing finishes its when the backup starts thats the problem, it shows eta at 20 days for 100 gb

  • 3. Re: Why is time mechine so slow on mountain lion
    Canadianpj Level 1 Level 1 (0 points)

    This is happening to me as well, it's telling me 15 hours left to finish backing up the 400GB of data on my drive and that amount of time keeps increasing. It is moving files but this is insane that it is taking to long and I doubt and this time it will even be able to complete successfully.


    There are numerous threads on this all over the place, another serious bug I think in ML.

  • 4. Re: Why is time mechine so slow on mountain lion
    bas valade Level 1 Level 1 (0 points)

    I found the way to fix this on the message boards (thanks to Swiggen).


    Check if your spotlight is indexing. If it is, let it finish, even if it takes days before plugging in your ext hard drive.


    Mine didn't seem to be busy indexing, so I stopped the indexing function (through Terminal) and then restarted the function. It then indexed for 2-3 days.


    Once it was finished, I plugged in my external hard drive and Time Machine started up and did a backup of 118gb in a few minutes.

  • 5. Re: Why is time mechine so slow on mountain lion
    Eric Root Level 6 Level 6 (16,210 points)