Resolved Why Time Machine backs-up so much when nothing has changed?

Discussion in 'Mac Basics and Help' started by Akarin, Oct 19, 2011.

  1. Akarin, Oct 19, 2011
    Last edited: Oct 19, 2011

    Akarin macrumors 6502

    Akarin

    Joined:
    Oct 16, 2011
    Location:
    Nyon, Switzerland
    #1
    Hi all,

    I have a little question regarding time machine (and yes, I am new to Mac). I noticed that every hour, it does its back-up on my external 1TB drive but... ...when nothing has changed (and I mean nothing as I was not using it), it still backs-up about 15GB of files. Why is that? Isn't it a differential back-up based on filesystem that would just copy the new/updated files?

    Thank you for your answers.
     
  2. r.j.s Moderator emeritus

    r.j.s

    Joined:
    Mar 7, 2007
    Location:
    Texas
    #2
    Are you not using the computer at all?

    Do you have a virtual machine running during that time?
     
  3. AcesHigh87 macrumors 6502a

    AcesHigh87

    Joined:
    Jan 11, 2009
    Location:
    New Brunswick, Canada
    #3
    It make sense for TM to run a backup even when nothing has been done, it's scheduled to do so. Something does seem up though if it's backing up that much. 15GB is a huge backup for me even when I have been using my mac. If it I haven't been the backup is usually only a few MB.
     
  4. Akarin thread starter macrumors 6502

    Akarin

    Joined:
    Oct 16, 2011
    Location:
    Nyon, Switzerland
    #4
    Nope. Nothing.

    Not doing anything at all. For example, I left it on this night, did nothing, nothing running, no downloads in progress and I manually backed it up before going to bed. This morning, I log in (it was still on), I click on "back up now" on the Time Machine icon in the status bar at the top and bam : copies 15GB. Is it strange?
     
  5. ctucci macrumors regular

    Joined:
    Dec 16, 2008
    #5
    Same here, but I do run a VM. I've always assumed TM had detected changes in that big VM file.

    I don't suppose it could be something like the equivalent of a large email database file ( like the one outlook 2011 for mac uses )? Something that could change frequently enough just by normal automatic email program checking?
     
  6. Akarin thread starter macrumors 6502

    Akarin

    Joined:
    Oct 16, 2011
    Location:
    Nyon, Switzerland
    #6
    It's exactly that ! My Outlook 2011 db is about 15GB and I have tested this:

    - manual back-up with Outlook closed: ±1MB
    - manual back-up after receiving ONE mail in Outlook: ±13GB

    I wouldn't have thought of that but you nailed it. Thanks for that. It is not a problem as I don't mind my external drive running and copying, I only use it for back-ups but I wanted to know why :p
     
  7. ctucci macrumors regular

    Joined:
    Dec 16, 2008
    #7
    Glad to contribute!
     
  8. AcesHigh87 macrumors 6502a

    AcesHigh87

    Joined:
    Jan 11, 2009
    Location:
    New Brunswick, Canada
    #8
    Glad you figured that out. I would say exclude wherever that is saved or, better yet, just use the mac mail application. works better and doesn't have that problem.
     
  9. garycurtis macrumors 6502

    Joined:
    Sep 15, 2010
    Location:
    Los Angeles & Northern California
    #9
    I have the same question. With little activity, backups to TM over a Firewire 400 cable take nearly 1/2 hour.

    Most of my email is Google mail, so that's in the Cloud. But I have Apple Mail (OS 10.5.8). Which are the data files there to exclude (including the complete path)?

    Thanks
     

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