Time Machine: 17+GB backups? Really?

Discussion in 'OS X Yosemite (10.10)' started by scaredpoet, Aug 14, 2014.

  1. scaredpoet, Aug 14, 2014
    Last edited: Aug 14, 2014

    scaredpoet macrumors 604


    Apr 6, 2007
    Seriously, there is no way that 17GB or more of data has changed on my iMac within the hour that the last Time Machine Backup was completed. This was never the case under Mavericks. And yet here is Yosemite, backing up multiple gigabytes of data every time a backup is initiated. Over and over again. And it's SLOOOOW. Sometimes taking well over an hour to complete.

    Is there any way to find out what exactly Time Machine is finding that's unique, and backing up every time? I have less than 300GB on my local storage, and my 4TB Time Machine drive is starting to fill up all of a sudden.
  2. BenTrovato macrumors 68030


    Jun 29, 2012
    I had a 40gb backup fire away today on my MBA. I have no idea how that would be possible. No files were copied or deleted. I was only browsing and typing emails over he past few days. The backup an hour before was less than 300mb.

    Interestingly enough the free space on the 1tb capsule is always 368gb free, it never changes from that amount. Starting to think something is fishy with the technology.
  3. oMc macrumors 6502


    Oct 17, 2010
    Finland & France
    Are you using a virtualization product, such as VirtualBox, Parallels, or VMware?
  4. rockinwaggy macrumors newbie

    Aug 14, 2014
    IIRC, Macbooks (maybe Desktops as well, not sure) now store old/deleted files locally to be transferred to Time Machine at the next backup, thus why your backup size was so large. I imagine your disk usage suddenly dropped after your latest backup too when it cleared off all of the transferred data.

    I think it was an addition to Mavericks, maybe even ML. Not sure as I never use Time Machine after SL which did not have that function.

    Screenshot for verification. It's of Yosemite, but the functionality is the same as before.

    Edit: Looks like it's been there since Lion (the Windows ME of OS X). Apple page here for confirmation >> http://support.apple.com/kb/HT4878

    Attached Files:

  5. kappaknight macrumors 68000


    Mar 5, 2009
    Mmm, well, this does happen in Mavericks. Every once in awhile Time Machine will say they need to create a brand new backup because the old one was no longer stable.

    I wonder if the "new" process is that it'll just do it without warning you. (I hope not, but that may be what's happening.) Most people won't check how old their backups go back to as long as there is a copy of it on the network.
  6. scaredpoet thread starter macrumors 604


    Apr 6, 2007
    Nope, using none of these.


    In my case (an iMac) there was no change to disk usage, other than the external Time Machine volume wasn't grinding away anymore until the next backup. Not sure why there would be use of a local Time Machine cache as the iMac hadn't gone to sleep and the drives never disconnected. Oh well. I may just turn automatic backups off until the final release of Yosemite.

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