Skip navigation

Time machine backing up has gone nuts!

160 Views 2 Replies Latest reply: Jul 25, 2013 11:33 AM by Linc Davis RSS
AceNeerav Level 1 Level 1 (80 points)
Currently Being Moderated
Jul 25, 2013 10:23 AM

Configuration: MBP mid 2010, 13 inch, SSD 120 GB, Ram 8 GB, TM Drive 1 TB external Seagate. Running on Mountain Lion 10.8.4


For some unknown reason, TM backin up seems to go on endlessly and the backup size keeps on growing. This has been happening for about a week! As a result the machine wont sleep for several hours. the backup size usually goes up to as much as 25 GBs!


Can someone tell me whats going on?



MacBook Pro, OS X Mountain Lion (10.8.2), 13 inch, 2.4 Ghz, Mid 2010
  • Eric Root Level 6 Level 6 (14,025 points)
  • Linc Davis Level 10 Level 10 (108,160 points)
    Currently Being Moderated
    Jul 25, 2013 11:33 AM (in response to AceNeerav)

    Do you use virtualization software, such as VMware, Parallels, or VirtualBox?


    The virtualization software creates a large virtual-disk container that is constantly changing, so it has to be backed up every time Time Machine runs. That will quickly fill up any backup destination.


    You should exclude the virtual-disk file(s) from your Time Machine backups. To do that, click the Options button in the Time Machine preference pane. Back up the files on the virtual disk from within the guest system, using a native backup application.


    A compromise solution is to create a "snapshot" of the virtual machine in the virtualization software (not a Time Machine snapshot.) That will give you a single large file that never changes and only has to be backed up once. All the subsequent changes will be stored in a new file that's initially much smaller, but will grow over time. You should still exclude that file from TM backup. If you ever need to restore the VM from Time Machine, you'll have a working setup, which will make it easy for you to restore the rest of the data from within the guest system.


    Another common cause of large TM snapshots is native OS X disk images. If you store a lot of data on one or more writable disk images, they should be in "sparsebundle" format, which will be backed up much more efficiently than any other format. Also be aware that disk image files are not backed up at all while the image is mounted. Make sure you unmount the image often so it can be backed up. If you ever restore, you will, of course, lose all changes made since the last backup. Consider eliminating large read/write disk images from your workflow, if possible.


More Like This

  • Retrieving data ...

Bookmarked By (0)


  • This solved my question - 10 points
  • This helped me - 5 points
This site contains user submitted content, comments and opinions and is for informational purposes only. Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site. All postings and use of the content on this site are subject to the Apple Support Communities Terms of Use.