How much space does a Time Machine backup require?

Discussion in 'MacBook Pro' started by bailmdb, Jan 4, 2011.

  1. bailmdb macrumors newbie

    Nov 2, 2009
    Over there
    I have a 15" MBP with a 250GB HDD. I have about 150 gigs free, so obviously only 100 gigs are in use. So if I use my external HDD to backup to Time Machine, will I only need 100 gigs of it, or will Time Machine need the full 250GB for the backup? Appreciate the insight.
  2. miles01110 macrumors Core


    Jul 24, 2006
    The Ivory Tower (I'm not coming down)
    It will do incremental backups of all the changed files and will take up as much space as you give it after a certain amount of time.
  3. newdeal macrumors 68020

    Oct 21, 2009

    It will use 100gb to backup and then as you add things it will add to the backup. In all you should probobly use a 500gb drive but it will take years to fill it with just backups.
  4. RichyB macrumors regular

    Dec 8, 2010
    I don't suppose there is a way to be more specific in what you want time machine to back up i.e. documents and safari settings.
  5. johnnyturbouk macrumors 68000


    Feb 9, 2011
    on the yellow [oled] brick road to tech nirvana.
    i have around 50gb on my ssd and 110gb on my optibay hdd
    my time machine is appox 165gb

    i would also ensure that the external hdd u use is formatted to hfs+
    and if you have media on there, to partition the hdd, with one, the remaining for media/personal files amd this partition is in fat32 so i can connect it via usb2 to my router
  6. Macsavvytech macrumors 6502a


    May 25, 2010
    Initial backup is the amount of space used on your main drive, after that incremental backups, backup whatever has changed. I have found with ~30 GB of data on my main drive I can use ~85GB of my Time Machine partition of my external hard drive. I do have a habit of copying big files on and off my main drive very frequently and this is represented in my backups where I have some that have only backed up 10MB and some that have backed up 10GB.

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