Time Machine Reports 'Full' with 20 GB Free

Discussion in 'Mac Basics and Help' started by PetC, Sep 2, 2009.

  1. PetC macrumors newbie

    Joined:
    May 15, 2009
    #1
    Time Machine is reporting the destination drive is full and asking me to allow it to delete the oldest backup done only a week ago, yet the drive reports it has 19.88 GB free. I have a 175 GB partition on an external HD backing up about 100 GB of my MacBook Pro (OS-X; V. 10.5.8). I thought TM backed up weekly and monthly but I am getting nowhere near that. How is it that TM is not using 20 GB of this free space?
     
  2. madog macrumors 65816

    madog

    Joined:
    Nov 25, 2004
    Location:
    Korova Milkbar
    #2
    It's possible that the changes you have made exceed that 20gb, in which TM is just refusing to backup. Otherwise, Time Machine saves the hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for everything older than a month.

    I think the rule of thumb is to have a backup that is at least double the size of the source. At the very least I would recommend possibly excluding the system folder (by default it backs up everything, other than what you manually exclude) from the backup.
     
  3. RedTomato macrumors 68040

    RedTomato

    Joined:
    Mar 4, 2005
    Location:
    .. London ..
    #3
    Do you run VMWare or Parallels? Both create large VM image files that contain your virtual machines, and TM often likes to re-backup the whole 20GB image even if all you did was load Windows for a few minutes.

    Ripping a few DVDs will often fill up TM too as TM backs up the rips you made.

    Solution: either get a larger TM drive (they're cheap nowadays) or exclude some folders from TM, and also make a 'large file' folder where you can put large files that you dont need backed up.
     
  4. PetC thread starter macrumors newbie

    Joined:
    May 15, 2009
    #4
    I do run Parallels from time to time, but I still don't understand why that would effect the amount of FREE space left on the external backup drive. The whole master drive holds about 142 GB and I have excluded pictures, music and videos, backing up about 100 GB on a 175 GB external drive partition. Today the report says only 16.12 GB free - now less than my initial post here. Would I be wise to exclude the Parallel's folder (or wherever the image file is) and expect the drive to fill up to 'full'? I wonder how much free space TM requires on the backup drive to do its magic?
     
  5. Ashka macrumors 6502a

    Ashka

    Joined:
    Aug 9, 2008
    Location:
    New Zealand
    #5
    Rule of thumb for TM Drives is twice the size of your Mac Hard Drive..
    Hard drives need working room, 15% on your main drive probably the same on a TM Drive
     
  6. RedTomato macrumors 68040

    RedTomato

    Joined:
    Mar 4, 2005
    Location:
    .. London ..
    #6
    Yes, excluding the folder where the Parallels VM files are is a good idea. I suppose you have things like MS Office and a few games in your Parallels Windows VM installation. That could be 20GB or more.

    Parallels (and VMWare Fusion too) take that whole 20GB and make it into a single massive file. Suppose you open Windows and play a game or something or make a new file. Now that 20GB file has slightly different contents, and TM sees it as a new 20GB file, and saves a new version.

    Do that each day for a week and that's 140GB of free space gone from your TM drive.

    Twice the size, yes. 15% working room - not really. TM should delete old files when it runs out of room.

    1TB drives are cheap. I have a 1TB TM drive dedicated to backing up my macbook. Actually I have two - one at home and one at work.
     

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