Time Machine Question

Discussion in 'macOS Virtual Machine' started by JohnNash, Apr 4, 2013.

  1. JohnNash

    JohnNash Member

    Messages:
    39
    I recently started using Time Machine to back up my VM's and have a general question to see if I'm doing something wrong. From reading the documentation, it's saying that a snapshot of the VM is generated every 48 hours (using default settings), which is is what's backed up rather than TM backing up the entire VM every hour.

    The issue that I'm having is that I'm backing up anywhere between 8 and 20gb an hour rather than every 48 hours. While that could be considered "good" from a disaster recovery standpoint, obviously if you do the math, I'm going to zero out my TM disk at some point and then it'll start trimming backups to continue backing up. While I know that's an eventuality anyway, I would rather be efficient in backing up rather than eat up the space quickly for no reason.

    I couldn't get the attachments button to actually allow me to upload a file, but a screen cap of my backup settings for my VM is at http://sdrv.ms/YURp1E . Can anyone give me some direction as to what to do?

    BTW - shortly after I started writing this post, TM started it's backup, which is the first since 1030am yesterday. 43GB in total. This is atypical of what I normally get (8-20gb) but just wanted to throw that in there...



    Thanks in advance


    Edit -realized I probably should have posted this under the configuration section., sorry.
     
    Last edited: Apr 4, 2013
  2. JamesBucanek

    JamesBucanek Bit poster

    Messages:
    5
    John,

    Since no one has answered you, allow me to chime in.

    Time machine backups up your documents hourly, which is why you're seeing the copy activity that you do. Furthermore, Time Machine just copies files that have changed. If you're using your VM file, Time Machine will attempt to copy the entire 20+GB file every hour. To make matters worse, TM discards older backups as soon as it runs out of disk space. At 20GB/hour, it won't take long before it starts throwing things away. Finally, you can't make an accurate copy of your VM while it's running.

    (Shameless commercial endorsement:) I developed a program called QRecall (<http://www.qrecall.com/>) that's specifically designed to address most of the limitations of Time Machine and other backup solutions that mindlessly copy whole files. QRecall is particularly efficient at backing up gigantic files with a modest number of changes (like VM files) using block-level de-duplication. You can also schedule QRecall to run when you're not running Parallels, such as when you log out.
     

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