Question: Q: System Storage Taking Up Way Too Much Space in macOS Sierra



Dec 15, 2016 2:49 PM in response to bindex


In response to bindex


The “System” category appears to be including sandboxed application data, which is stored in ~/Library/Containers/.

I used About This Mac | Storage | Review Files | File Browser to navigate to the folders/files using the most space and found that Docker was growing a file called Docker.qcow2 indefinitely in ~/Library/Containers/. Deleting the file released 30GB from “System” while “Documents” stayed the same size.


Dec 12, 2016 6:38 AM in response to bindex


In response to bindex


There are at least two previous posts regarding the same “issue” (if in fact it is one!), but I’m not sure anyone has got to the bottom of it yet.

Is it normal that “system” takes up 36 gb of storage? What does is contain? Can it be decreased?

From my own experience I’ve found out that “iTunes” (yes, I seem to have that showing in the left side) only reports size for Apps and Podcasts – my Music which is nearly 70Gb looks as though it’s reported under “System” (as you have found) which is currently at 83Gb – can’t confirm because as you state it’s greyed out, but all the other items on the left are far less in size so “System” seems the only place the machine has found to report my music content.

Furthermore, if I use Finder and add my actual Music size (70Gb) to Macintosh HD System and Library (8Gb + 5Gb) it gives 83Gb (what the greyed out “System” is reporting).

So I’ve basically given up trying to understand why it’s reporting in the way it is – the concern previously was of a bloated System file section, but that doesn’t seem to be the case (and Finder proves that), so may be it will all get sorted in a future update!


Dec 31, 2016 1:00 PM in response to bindex


In response to bindex


I found how to purge half of the system on my mac.

I downloaded OmniDiskSweeper which I accessed and I found that under a folder called fsCached Data, there was about 60GB of cached data. I deleted all of it, which was about 200,000 items and it immediately fixed my system problem, which was originally 87GB. It has dropped down to 27GB now with that.


Dec 12, 2016 1:48 PM in response to Ample Apple


In response to Ample Apple


Just tried your suggestion but it has made no difference (thanks for trying anyhow), System at 83Gb before, during Safe Mode (after it recalculated) and finally on reboot – still showing 83Gb!

It’s worth noting my issue is not incorrect reporting of disk space usage, but rather what it is being recorded against – if it would stop putting music under System and instead show it under iTunes all would be well.


Dec 31, 2016 2:05 PM in response to bindex


In response to bindex


I don’t think this will solve your iTunes issue, but I’ve had a similar issue on two Mac machines, both from the same source: Adobe cache files. On my newer Sierra Macbook the “System” storage was reporting as 186Gb on my 250Gb SSD. Now that I’ve fixed it “System” is less than 20 Gb.

OmniDiskSweeper is a great tool for this, although there are other ways to fix it.

(Be sure you get Version 1.9 or later. The first time I tried, I went to the wrong source and got an earlier version, which didn’t work on Sierra.)

Look at the following path: Users>”YourUserName”>Library>Application Support>Adobe>Common>Media Cache Files. Delete everything in this folder.

In my case, this folder contained full copies of every video that had ever been on the machine. Plus, if I had renamed the video, say from “Beach1” to “Beach2”, it had full copies with both names. It has additional smaller files for each video, and it may be caching image files as well, although I didn’t look at every file.

This is especially weird since I copy newly shot videos from the camera card to the laptop in the field (so I can look at them quickly with Flip Player.) I do not ever edit video on this machine, or open video with any Adobe editing product. I do have Bridge, which makes thumbnails of the videos if I happen to use it to look at that folder.

I had the same problem a year or two ago on an earlier machine, fixed it, and I thought Adobe had fixed the bug. But apparently not.


Feb 23, 2017 11:39 PM in response to bindex


In response to bindex


You have to take into account all the other files on your Mac, not just iTunes.

For example the text messages on my iPhone determine the size of the backup my iPhone does on the cloud.

You need to look into how many notes you have and how many text you sent on the macbook. iTunes isn’t the only thing taking up space in the system storage tab. It would also be easier for us to help if you submitted a screenshot of the actual Documents>iTunes folder so we can see the size of the folder. That will give us all the info we need to determine the issue. My library is taking up space on my MacBook Air mainly because I use Apple Music and the library takes up space if I use it on my MacBook. Some files are stored on the mac. When I went to my iTunes Music folder in Finder I found what was taking up all the space. It was a movie I purchased on my MacBook Air. One movie was taking up 7GB of data. Go into iTunes and find the movie then select remove download and you can see in the iTunes folder in finder where the folder was removed and the space is now back when I go to System Information. I can delete it and still watch it on all my devices because of the purchase history option. Now what is taking up all the space is a folder titled Album Artwork.

My iTunes Library on my iMac is 4,185 albums, 176 days, 435.37GB so I’d say I’m doing great for having that available on my MacBook Air anytime I want and the System Storage is only now 35.1GB.

Do some digging around in Finder and I’m sure you will find the file(s) taking up all your space. Till then submit the screenshot with more info on the breakdown of the files within iTunes and I’ll be able to tell you where to look next. There are a lot of folders you will need to look into if iTunes is not the issue. For instance you will have to go into your Caches folder and see what is in there. There is a lot that can be done, but I don’t want to list them all here and misdirect you when you probably don’t need to go into these folders.


Dec 22, 2016 1:56 PM in response to bindex


In response to bindex


– Using the Disk Daisy (https://daisydiskapp.com/) trial version allowed me to pinpoint which directory was causing the issue

– In my case, it was the .DocumentRevisions-V100directory which is where Sketch dumps older versions of your documents

– I followed the steps outlined on this post: (https://medium.com/sketch-app-sources/sketch-can-unknowingly-take-way-too-much-h ard-drive-space-here-s-how-to-fix-it-1979e976f2d6#.libhod8u4) and Voila! Solved!

*Keep in mind that even if you aren’t a Sketch user, these steps might still help you. Good luck!


Dec 12, 2016 6:38 AM in response to bindex


In response to bindex


There are at least two previous posts regarding the same “issue” (if in fact it is one!), but I’m not sure anyone has got to the bottom of it yet.

Is it normal that “system” takes up 36 gb of storage? What does is contain? Can it be decreased?

From my own experience I’ve found out that “iTunes” (yes, I seem to have that showing in the left side) only reports size for Apps and Podcasts – my Music which is nearly 70Gb looks as though it’s reported under “System” (as you have found) which is currently at 83Gb – can’t confirm because as you state it’s greyed out, but all the other items on the left are far less in size so “System” seems the only place the machine has found to report my music content.

Furthermore, if I use Finder and add my actual Music size (70Gb) to Macintosh HD System and Library (8Gb + 5Gb) it gives 83Gb (what the greyed out “System” is reporting).

So I’ve basically given up trying to understand why it’s reporting in the way it is – the concern previously was of a bloated System file section, but that doesn’t seem to be the case (and Finder proves that), so may be it will all get sorted in a future update!


Dec 12, 2016 1:48 PM in response to Ample Apple


In response to Ample Apple


Just tried your suggestion but it has made no difference (thanks for trying anyhow), System at 83Gb before, during Safe Mode (after it recalculated) and finally on reboot – still showing 83Gb!

It’s worth noting my issue is not incorrect reporting of disk space usage, but rather what it is being recorded against – if it would stop putting music under System and instead show it under iTunes all would be well.


Dec 15, 2016 2:49 PM in response to bindex


In response to bindex


The “System” category appears to be including sandboxed application data, which is stored in ~/Library/Containers/.

I used About This Mac | Storage | Review Files | File Browser to navigate to the folders/files using the most space and found that Docker was growing a file called Docker.qcow2 indefinitely in ~/Library/Containers/. Deleting the file released 30GB from “System” while “Documents” stayed the same size.


Dec 22, 2016 1:56 PM in response to bindex


In response to bindex


– Using the Disk Daisy (https://daisydiskapp.com/) trial version allowed me to pinpoint which directory was causing the issue

– In my case, it was the .DocumentRevisions-V100directory which is where Sketch dumps older versions of your documents

– I followed the steps outlined on this post: (https://medium.com/sketch-app-sources/sketch-can-unknowingly-take-way-too-much-h ard-drive-space-here-s-how-to-fix-it-1979e976f2d6#.libhod8u4) and Voila! Solved!

*Keep in mind that even if you aren’t a Sketch user, these steps might still help you. Good luck!


Dec 31, 2016 1:00 PM in response to bindex


In response to bindex


I found how to purge half of the system on my mac.

I downloaded OmniDiskSweeper which I accessed and I found that under a folder called fsCached Data, there was about 60GB of cached data. I deleted all of it, which was about 200,000 items and it immediately fixed my system problem, which was originally 87GB. It has dropped down to 27GB now with that.


Dec 31, 2016 2:05 PM in response to bindex


In response to bindex


I don’t think this will solve your iTunes issue, but I’ve had a similar issue on two Mac machines, both from the same source: Adobe cache files. On my newer Sierra Macbook the “System” storage was reporting as 186Gb on my 250Gb SSD. Now that I’ve fixed it “System” is less than 20 Gb.

OmniDiskSweeper is a great tool for this, although there are other ways to fix it.

(Be sure you get Version 1.9 or later. The first time I tried, I went to the wrong source and got an earlier version, which didn’t work on Sierra.)

Look at the following path: Users>”YourUserName”>Library>Application Support>Adobe>Common>Media Cache Files. Delete everything in this folder.

In my case, this folder contained full copies of every video that had ever been on the machine. Plus, if I had renamed the video, say from “Beach1” to “Beach2”, it had full copies with both names. It has additional smaller files for each video, and it may be caching image files as well, although I didn’t look at every file.

This is especially weird since I copy newly shot videos from the camera card to the laptop in the field (so I can look at them quickly with Flip Player.) I do not ever edit video on this machine, or open video with any Adobe editing product. I do have Bridge, which makes thumbnails of the videos if I happen to use it to look at that folder.

I had the same problem a year or two ago on an earlier machine, fixed it, and I thought Adobe had fixed the bug. But apparently not.


Dec 31, 2016 2:11 PM in response to greydog77


In response to greydog77


Forgot to say: When I get home from shooting, the videos are transferred to a desktop, and deleted from the laptop. The mystery cache files apparently stay behind.

Until Adobe re-fixes this bug, I’d like to find a way to write a script (or something) to clear this folder with one click. Any ideas would be appreciated.


Dec 31, 2016 4:32 PM in response to greydog77


In response to greydog77


You could try creating a folder on an external drive named Common. Use an alias or Symlink in place of Common folder. See if this saves the cached data to the external drive.

For easier creation of symlinks, you can add this script
http://cl.ly/ImZ5
to “User/Library/Services” and right click on finder items to create symlink.

How to Create Symbolic Links at Command Line of Mac OS X

https://gigaom.com/2011/04/27/how-to-create-and-use-symlinks-on-a-mac/