osx - Mac OS X Difference between actual and displayed space usage

08
2014-07
  • guenis

    I checked my Macbook Air's disk usage with 'ncdu' tool and found that there is a big difference between my actual space usage and the displayed one. It has a 128 GB SSD and it's running OS X Mavericks NCDU screenshot

    System tool screenshot

    Is there any way to make the storage more compact and save that lost space? Or is it normal to have such a discrepancy in SSDs and/or Mac OS X?

    • Answers
  • devnall

    Depending on how you deleted the files, you may need to run the sync command in a terminal. Rebooting should do the same thing, only better (see the sync man page).


    • Related Question

    osx - Good program to visualize file system usage on Mac?
  • Damien

    Based on this question, I would like to know if there are any good programs to visualize file system usage on OS X?

    I used to have SpaceMonger when I was using a PC and would love to find some alternatives for my Mac.


    • Related Answers
  • 8088

    Have a look at

    • Baseline
      • Superfast Disk Scanning
      • View files and folders in a list, in columns, or graphically as a TreeMap
      • Detect duplicate files
      • QuickLook support
      • Time Machine disk support
      • Compare your disk against saved Baselines
      • View only the items that have changed
      • Delete or Compress items to save space

    Baseline

    With DaisyDisk you can free up disk space by quickly finding and deleting big, useless files. The program scans any mounted disk and displays it on the sunburst map, where segments mean files and folders, proportionally to their sizes. The map is easy to read and navigate. You can also quickly preview any file and reveal it in Finder to delete.

    Daisy Disk

    A review of both the applications on SmokingApples

    OmniDiskSweeper is also another alternative.

    OmniDiskSweeper presents you with a list of disks attached to your machine. Double-click on one, and a new window opens with a “column” view listing every folder and file you can access, which it sorts by size as you watch.

    You then simply browse through the folders and files and delete the large ones which you are no longer using. If a file is part of the system, it'll say so on the panel (in the list of Packages the file belongs to), so you won't accidentally get rid of something that would make your system stop working. The free space on the disk and the ordering of the folders are automatically recalculated.

    OmniDisksweeper

    OmniDiskSweeper is freeware.

  • 8088

    JDiskReport is available as a JAR file. It will run anywhere that a JRE is installed, including your Mac.

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  • 8088

    You want Disk Inventory X.

    from the site:

    The layout algorithm is based on KDirStat. The idea to develop this program came to me when a fellow of mine showed me his creation WinDirStat.

    alt text

    Disk Inventory X is freeware.

  • 8088

    GrandPerspective is an Open Source app that will do what you're asking.

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  • ridogi

    WhatSize ($13) and Baseline ($20) both show you a view of all folders sorted by size which you can drill down into (among other view options). It is a little hard to describe, but much more useful than the graphical view of many of the other apps that have been listed. Baseline has more features such as making snapshots of your disk usage to compare to your current usage, but it is the more expensive of the two.