I am not a pro at Mac / OS X. But I know my way around.

I just installed OS X El Capitan. However when I first started up, my harddisk used 30GB with 'other'. With time the capacity just keeps shrinking. If I just stare at the screen, I just see the available space drop and drop. Until it hits Zero Bytes at capacity.

Does anyone know what I can do about this? I cannot seem to find anything on this on Google.

The only thing it returns on my keywords are things like how to remove temporary files, re-index size with Spotlight, Startup in safe mode. None of these things seem to work.

@Edit 22:02 06-04-2016

I have checked Activity Monitor and got the following results: enter image description here

I have sorted on Bytes Written, that does not seem very strange.

However if I check the Graph Data Written below it gives: enter image description here

As you can see the data Written is around 8.33 GB and a few minutes later already 10 GB,.. I checked; 'sudo fs_usage -f filesys' this keeps trying to get some attribute lists from mdworker? Don't know if that is normal?

@Edit 20:30 07-04-2016 With 'sudo fs_usage -f filesys' I see that the following processes write;

  • nsurlsession
  • nsurlstorage
  • IMRemoteUrlC
  • cfprefsd

With using Daisy Disk App I see the following: enter image description here

So the private and library grows a bit, however the Core grows massively. I see that it produces a 'core dump' of around 528 mb every now and then. This tells cores is a folder for a core dump;

OS X El-Capitan - /cores directory taking up a lot of space?

What/why is this happening? (Like the post I have set the core dump limit to 0 and it seems to have stopped generating.)

PS: This is not a duplicate of Over 25 gb of Space Disappeared, I do not have time machine / Backups turned on.

  • What software do you have installed on the Mac? Something must be manipulating data on your Mac. – slightly_toasted Apr 6 '16 at 17:58
  • Nothing, It is just a clean OS X El Capitan. I do see com.apple.iconservices.store keep coming back in the cache folder? – Revils Apr 6 '16 at 18:02
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    So if I understand correctly, your hard drive keep creating new data until it's full and has no more capacity to create whatever this data is? – slightly_toasted Apr 6 '16 at 18:04
  • Jep,.. I cannot find what it is. – Revils Apr 6 '16 at 18:05
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    data written / read might just be the pagefile (aka. RAM contents being put to disk to keep RAM load down). Download daisydiskapp.com (trial should do, no need to buy) and run an admin scan (hit the disclose arrow next to the scan button). Any files/folders look suspiciously massive? – kevin9794 Apr 7 '16 at 18:15

Ah, these are core dumps. You can find more information on why they happen and how to prevent them here. In a nutshell, they are generated for debugging, but shouldn't be kept on disk by default. Either the system setting is wrong, or some buggy process is choosing to save them. Running

sudo launchctl limit core 0 unlimited

in Terminal will disable the system from saving them by default, but still allow processes to make them if they choose to, or running

sudo launchctl limit core 0 0

will disable them entirely, both in the system by default, and by disallowing processes from creating them. There should be no issue if you disable them completely. 👍

  • It is for software developers and generated by crashes. Is this not strange for a fresh Mac OS X installation? – Revils Apr 7 '16 at 19:11
  • definitely is. Wouldn't surprise me if the installation process enables core dumps for all crashes, and disables them on completion. Maybe some bug or mishap prevented the installer from disabling them in this case. – kevin9794 Apr 7 '16 at 19:20

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