Size of time machine backup

Discussion in 'MacBook Pro' started by Ruggs, Mar 6, 2016.

  1. Ruggs macrumors newbie

    Ruggs

    Joined:
    Mar 6, 2016
    #1
    Hi there,

    I've recently had my 15" MacBook Pro stolen, it had a 750gb HHD (not full) and I had a full time machine back up. I'm looking to buy a replacement Mac and Install everything back from the time
    Machine back up but I'm not sure if my backup is bigger or smaller than 512gb (retina Mac). When I plug the time machine hard drive into another Mac and check 'get info' it states that it's used 799gb.

    Any help appreciated
     
  2. Spudlicious macrumors 6502

    Spudlicious

    Joined:
    Nov 21, 2015
    Location:
    Bedfordshire, England
    #2
    That reported 799GB size is the total of disk images from every date that TimeMachine ran, and the one you choose to restore will be much smaller.
     
  3. Ruggs thread starter macrumors newbie

    Ruggs

    Joined:
    Mar 6, 2016
    #3
    Is there any way to find out exactly how big it is?
     
  4. priitv8 macrumors 68020

    Joined:
    Jan 13, 2011
    Location:
    Estonia
    #4
    Just open (or mount) the backup in Finder, highlight the backup folder you are interested in and issue Get Info command.
    Screen Shot 2016-03-07 at 8.21.08.PNG
     
  5. Ruggs thread starter macrumors newbie

    Ruggs

    Joined:
    Mar 6, 2016
    #5
    Thanks will try today
     
  6. Spudlicious macrumors 6502

    Spudlicious

    Joined:
    Nov 21, 2015
    Location:
    Bedfordshire, England
    #6
    TimeMachine splits backups into numerous files of 8KB size, but it is not obvious to me how those are organised. Looking at a backup I have on a network drive I see in excess of 20,000 files for a total of 163GB, but I actually use less than 50GB of the 256GB on my Macbook.
     
  7. priitv8 macrumors 68020

    Joined:
    Jan 13, 2011
    Location:
    Estonia
    #7
    Technically, Time Machine uses still full copies of files. To save space no duplicates are written, only hard links to original copy. Thus the file count grows with every backup, but the size only grows by amount of new/changed files.
    Thus the total file count and backup total size are just indicators of your history weight.
    The 8KB files you mention, must be the bands of a sparsebundle, not the backup content. Sparsebundle is a expandable/contractable disk image, Time Machine uses when backing up to network volumes.
    You can find more details on Pondini's excellent site: http://pondini.org/TM/Works.html
     
  8. Ruggs thread starter macrumors newbie

    Ruggs

    Joined:
    Mar 6, 2016
    #8
    Found out my lastest back up is 548gb. What will happen if I try to install this onto a 512SSD will I be able to pick what I don't want put on? My music and programs are the main things I need.
     
  9. iMacDragon macrumors 65816

    iMacDragon

    Joined:
    Oct 18, 2008
    Location:
    UK
    #9
    Not sure about restoring backup, but machine migration assistant can use time machine as a source and let you pick what to transfer iirc.
     
  10. priitv8 macrumors 68020

    Joined:
    Jan 13, 2011
    Location:
    Estonia
    #10
    Time Machine will not restore if backup is larger than destination disk. You have 2 options:
    a) remove excessive files from backup before restoring (use Time Machine UI of Finder, gear button on toolbar)
    b) copy files from T M backup manually to destination drive using eg Finder or command-line. This will be trickier than it sounds. To restore to system drive, you need to boot from external or recovery partition. You need to make system disk bootable. You need to know exactly what files and folders to restore. This is especially true for apps, that used installer packages. This usually means they installed also drivers, launchd scripts, configuration files and the like. It will be much more painless to just rerun the installers, instead of copying.
    Your personal files, preferences etc are restored easily by just copying the home directory from backup folder to destination drive.
     
  11. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #11
    A third way that might work out for the OP would be to use Migration Assistant then when you get to this screen, deselect enough of the large categories to get down to a size that will fit on the SSD. For example, you could uncheck Music there and avoid transferring a large iTunes library. Then later put the iTunes library on an external drive.

    iur.png
     

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