Currently Being ModeratedAug 6, 2012 3:24 PM (in response to fahmi5389)
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.
Currently Being ModeratedAug 6, 2012 9:35 PM (in response to dwb)
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
Currently Being ModeratedAug 6, 2012 9:38 PM (in response to fahmi5389)
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.
Currently Being ModeratedDec 6, 2012 7:59 AM (in response to fahmi5389)
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.
Currently Being ModeratedDec 6, 2012 11:07 AM (in response to fahmi5389)
Maybe this will help: