My Mac's hard drive is filling itself. I just freed 10 more GB this week and I am stuck at 0 bytes free. My computer is ultra slow and sometimes won't even boot as the disk is full. When this happens I have to go to Safe Mode, delete 1 or 2 GB of files I find, and then it fills itself up again.

I have a 2011 MBA, running macOS 10.9 Mavericks.
I ran sudo find / -size +500000 -print and deleted as many files as I could.

Does anyone have any idea what could be filling up my Mac?


6 Answers 6


For me it was a lot of old xcode app archives and device support for previous iOS versions.

I used DevCleaner for Xcode to free up a ton of space.

The app is free and was simple to use. I'm not affiliated in any way.


I found what was actually filling up my disk.


was 90G and growing.

I used DaisyDisk and analysed the disk in Administrator Mode (OmniDiskSweeper wasn't showing admin files).

I found on the internet that a lot of people had the same troubles.

Just open up a terminal and execute.

sudo rm -rf /System/Library/Caches/com.apple.coresymbolicationd/ 
  • Out of curiosity, do you build a lot of software? That's what seems to trigger it losing its mind for me.
    – Matthew G.
    Sep 17, 2019 at 23:00

There are multiple apps/features such as Dropbox, OneDrive and iCloud that allow you to backup files to the cloud and then sync them between computers.

It is my guess that you have one or more of these enabled and it is automatically downloading these files to your computer in an attempt to sync your computer with the remote storage.

One example is when a person uses Dropbox and is a member of a shared folder. Even if you delete the files locally it may continue to re-download those files.

  • Deleted most of my files, no more Dropbox since two weeks and performed a rm -rf on dropbox files. Never had iCloud actived ou OneDrive. Thanks for suggestions.
    – Jean G
    May 3, 2018 at 11:05

Presumably it's not obvious from the find...-print what app/process is generating those files.

You could use Activity Monitor's Disk tab and sort processes by Bytes Written. In an otherwise quiescent system the culprit should stand out like a sore thumb.

  • Didn't thought about it. Checking right now. Thanks. (waiting for it to fill itself).
    – Jean G
    May 3, 2018 at 11:06

I suspect that files migrate between iCloud and the Mac memory. If you watch the memory size on About This Mac, the file size is not stable one minute to the next and I suspect that parts of files become corrupted of detached and thus become unidentifiable.

I have turned off iCloud totally an the machine is much more stable and the memory seems stable too. I have completely reinstalled so it remains to be seen whether this fixed the problem.

I do not have tangible evidence of this but the set up, a large remote computer and a small machine with limited space, invites instability it seems to me.

Apple do not seem to address or even discuss the problem so it may be that it is something beyond their scope to fix and so is best ignored. Best forget iCloud and buy some plug in memory.


In my case Catalina was saving a copy of the default desktop mage about once per second. Overnight this used up 300GB or so. I changed the default desktop image to one of my own photos and problem disappeared. The images were being written to a folder /private/var/folders/II/n85fg70121zgxw........../T deleting this T folder freed up all the disc space. Daisy disk helped me find the folder that was 300GB or more.

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