I've been using an app called JDisk report which pinpoints the biggest space hogs on my drive. I've been trying to run it on the family iMac but the results are quite inaccurate because the only thing my user account has permission to access (and therefore the only thing it can scan) is my user folder, shared folders and public folders. I tried using the chmod command which I though would change the permissions of the folder to which it was executed on and all folders within, but it only does it per-folder, which makes the process extremely tedious. There must be a better way to do this.

If it helps, I'm running macOS 10.13.6 High Sierra on a mid-2011 iMac (base 500GB model except the RAM has been buffed to 12GB)


chmod has an -R option to apply changes recursively to a whole directory tree but I strongly recommend to not use it for your scenario as you can break quite a lot of things by applying it in places where you shouldn't.


  • Log into your Mac as an administrative user and rerun JDisk. Not sure it will solve all your issues though as the tool seems to be cross-plattform and may not be aware of access right handling on macOS
  • Check out the answers in How can I figure out what's slowly eating my HD space? for other tools
  • If I just use it for user folders, surely it won't break anything? I am already an admin and this doesn't seem to have any effect. Aug 10 '19 at 11:33
  • @john If you just use it for your own folders beneath /Users/YOURUSER the potential risk is small, but you shouldn‘t have access issues there anyway. In any case I would make sure to have a recent backup before trying anything fancy.
    – nohillside
    Aug 10 '19 at 12:16

I would recommend OmniDiskSweeper or DaisyDisk as native Mac tools that can sort the entire volume by size, showing you what's using the space (and even delete it from within the app).

Apart from large application support files like sample libraries for Garageband, Logic, etc; then content in the User domain is likely to be the only thing that you can safely delete (and also the stuff that's taking up all the space).

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