Disk Usage by "System"

Discussion in 'MacBook Pro' started by sgharp, Jan 15, 2017.

  1. sgharp macrumors newbie

    Joined:
    Dec 29, 2012
    Location:
    Canton, GA USA
    #1
    Hi,

    I have a mid-2012 MacBook Pro with a 750GB SSD. I've been fighting with frequently running low on disk space for some time. I noticed today that "System Information/Storage" shows that "System" is using 532GB or more that 70% of my drive. My entire user directory uses less that 200GB and I'm still running out of space. How can so much space be allocated to System and how do I free it up?

    Thanks for any suggestions....
     
  2. Wildkraut macrumors 6502

    Joined:
    Nov 8, 2015
    Location:
    Germany
  3. sgharp thread starter macrumors newbie

    Joined:
    Dec 29, 2012
    Location:
    Canton, GA USA
    #3
    I don't. After reading up on it, I'm not sure I want to. Apple doesn't really ensure results.

    Why do you think this would fix the problem?
     
  4. xraydoc macrumors demi-god

    xraydoc

    Joined:
    Oct 9, 2005
    Location:
    192.168.1.1
    #4
    There's a number of apps that will show you what is using all your space. One I like is Daisy Disk. It's a few bucks on the Mac App Store.
     
  5. sgharp thread starter macrumors newbie

    Joined:
    Dec 29, 2012
    Location:
    Canton, GA USA
    #5
    I've used OmniDiskSweeper and it only shows a little over 200GB used. However, OSX System Information shows almost the whole 750GB used. When I use a terminal, df also shows the drive almost full.
     
  6. HDFan, Jan 15, 2017
    Last edited: Jan 15, 2017

    HDFan macrumors 6502

    Joined:
    Jun 30, 2007
    #6
    I would check that OmniDiskSweeper is giving the correct results. On my system it hung on the Users directory, the most likely place you could be using a lot of space.

    It was also quite slow. I could have done multiple DaisyDisk full volume scans scans while Omni was just scanning one large directory (Users). If you don't want to use DaisyDisk you might try to find another scanner to make sure that it gives the same results.

    Here are the screenshots of my results. I gave up waiting for Omni to finish after ~10 minutes so it is still chugging along. After ~30 minutes I updated this post with the "maybe a bug" comment. [This drive is an SSD on a 2013 nMP].

    Screen Shot 2017-01-15 at 19.59.50.png
    Screen Shot 2017-01-15 at 20.01.45.png
     
  7. maflynn Moderator

    maflynn

    Staff Member

    Joined:
    May 3, 2009
    Location:
    Boston
    #7
    Omnidiskspace dose not have the rights to access some system files and so it will under report them

    If you run it with sudo (As shown below), it will include some system files that it woud not normally have access to scan. That is a more accurate representation of what's consuming your drive.
    Code:
    sudo /Applications/OmniDiskSweeper.app/Contents/MacOS/OmniDiskSweeper
    Another option is to use this terminal command
    sudo du -d 1 -x -c -g /

    I prefer to redirect it to a text file (this puts it in your Documents folder
    sudo du -d 1 -x -c -g / > ~/Documents/du.txt

    Like the sudo /Applications/OmniDiskSweeper.app/Contents/MacOS/OmniDiskSweeper command, it will scan all directories, but produce a text file as opposed to showing the results in a window
     
  8. Wildkraut, Jan 16, 2017
    Last edited: Jan 16, 2017

    Wildkraut macrumors 6502

    Joined:
    Nov 8, 2015
    Location:
    Germany
    #8
    Because it looks like macOS isn't communicating right with the SSD.
    I think it's full because there is a lot of sector garbage left on then SSD, means they not flagged as free space for/by macOS.
    Trim is exactly to avoid this.

    https://en.wikipedia.org/wiki/Trim_(computing)
     
  9. sgharp thread starter macrumors newbie

    Joined:
    Dec 29, 2012
    Location:
    Canton, GA USA
    #9
    This was the solution. Running OmniDiskSweeper as a regular user prevents it from accurately reporting. I ran it as root and it turns out that /var/root/.cache was using over 400GB. Looks like leftovers from failed duplicity backups.

    Thanks very much! You save my bacon.
     
  10. Oleg K. macrumors newbie

    Joined:
    Mar 16, 2013
    #10
    Just FYI, there is "Scan as Administrator" command in DaisyDisk, which is essentially the same as running the app with sudo, but in a more convenient way. See https://daisydiskapp.com/manual/4/en/Topics/AdminScan.html
     

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