macOS High Sierra – Huge System Storage

I noticed that my disk space was being over ran by SYSTEMs Data (on MacOS HighSierra). I never had this issue in previous OS versions, but this was nearly half my storage!!!

Not to worry as there is a solution below:

I ran MacPaw's CleanMyMac Pro, but it only aleviated 9.91GB of space. That means theres something else thats eating away at this OS.

I kept digging and found this post. JamBeats mentioned that TimeMachine is storing snapshots on the local disk. I looked into it and found that I had a couple snap shots on my disk.

Code:

sudo tmutil listlocalsnapshots /

So I preceded to delete the snapshots on my local disk

Code:

tmutil deletelocalsnapshots <timestamp>

Once all these snapshots were deleted. I reviewed my Storage Disk and found it at 75.02GB in use.

This Fixed my Problem.

Thanks Everyone!

Manual but 100% effective mode ( without downloading software ).

Open Terminal... ( you will run as sudo so you can see all folders ). The du -hd 1 command is a utility that shows folder size and the one specifies a recursion level of one ( look at the immediate folders ).

1. cd /
2. sudo du -hd 1 .

You'll see a list of directories and sizes...

0B ./.config

535M ./Music

8.0K ./.vim

0B ./AppName.app

28K ./.subversion

8.0K ./.adobe

92K ./.local

1.8G ./Pictures

9.4M ./Desktop

51G ./Library

That last one looks huge! So repeat the process above...

1. cd Library
2. sudo du -hd 1 .

Keep repeating until you drill down to the folder that's the culprit. Then make decisions. Delete etc... If it is a time machine folder, do not delete those files, use the time machine utility. If its photos, do backups before deleting. If its something else do research.

Please check if you are using Mail.APP then you might have connection log option on and that is creating logs in to below folder.

Click Go Menu in Finder, Click Go to Folder copy and paste below location that contains Log files.

See File size that is huge for e.g imap.gmail.com *********.txt in My case Or similar. Copy and take back up in external HDD then Delete that file.

~/Library/Containers/com.apple.mail/Data/Library/Logs/Mail

You can disable this option form connection doctor in Mail.app.

Hope this will resolve your issue.

For anyone else with this issue, I recommend downloading Disk Wave as a few other people have suggested on various forums. This helped me realize that when I "added" a user to my Mac in order to change the name of it, it retained my entire library on top of the new one..basically I had a duplicate of my entire storage. So after deleting that, deleting my duplicate music files (and only keeping the "iTunes Media" folder versions, and moving old files to an external drive, I went from 75GB free to 380GB free!

I had this too. After scouring google for answers and trying everything from removing my Time Machine and removing its cache storage (did nothing). To resetting PRAM (did nothing) I FINALLY got on Apple Support Chat. My issue was escalated to senior tech Nicole. She helped me hunt down....HDHomeRun with a whopping 390GB in storage. I don't even have the version that's supposed to record so how is that happening??! Anyway, I rarely used it (which is why I never considered it to be the problem) so just uninstalled. Now my system is back down to reasonable 30GB with over 450GB AVAILABLE. So if you have some sort of digital antenna service..that could be it...somehow covertly storing huge data!
Just thought I would share my resolution because the problem is very frustrating and hard to find.

Had ostensibly the same problem, posting a reply in case anyone else needs another possible solution. I found out that my computer was attempting to create an unlimited number of "cores" which are described elsewhere as a kind of snapshot of the RAM at a time when a process isn't working properly. These can be about 500MB each - and when the computer makes 10 all of a sudden it chews up a lot of space.

To get rid of them, navigate to Macintosh HD (or whatever you've renamed the hard drive to), show hidden files, and then navigate to "cores". If you've got the same issue as me, you'll see a huge list of "cores" that you can delete. Thing is, your computer will keep making them until you solve the problem of what's actually creating the cores.

My issue with this problem started when I was prompted to update High Sierra and was told I did not have enough disk space on my 2011 MacBook Air. My system folder at the time was only 65G out of 250 (Bootcamp took 50 of the 250). I started deleting big files I no longer needed, but even after deleting them from Trash, my available space was not getting larger, the System folder was! This continued until my System folder was 198G! And I still could not update anything.

I tried everything I read here: deleted Time Machine snapshots, reindexing with Spotlight, but nothing worked. I tried installing a fresh copy of High Sierra over the original but couldn't because I didn't have enough disk space!! And I there was nothing I could do to create more, since ever app and file I deleted had it's HD space gobbled up by System!

Fortunately, I had a bootcamp partition on my HD and as a las resort, removed it and OS repartitioned my drive so I no had the full 250G. That gave me enough space to try an OS install. But that didn't help.

Before doing anything drastic, I spent and hour+ at the Genius bar, moving from apprentice genius to genius and finally to arch genius. No one saw this before or could help.

Before restoring to a new machine and moving files manually, I did a full back up to a fresh external drive and then command-R from boot up to restore from this back up. Viola! My system folder went back to 50+G and all was well.

Before:

After:

I was presented with a friends MacBook today which despite her removing as much un-needed stuff as possible had virtually no space left on the 120GB drive. Only a few MB remained. It was virtually impossible to do anything at all.

She had used the macBook for her business for a few years and had 2 email accounts used extensively day to day for corresponding with clients and sending forms etc. for bookings and the like. One account was with 1&1 the other with Sky. She has just sold her business and no longer needs the accounts but her machine was unusable.

When I looked in some detail by switching off both accounts to prevent further updating any attempt at a clean up just caused any space reclaimed to disappear within minutes. The culprit was principally her Sky account which contained emails going back to September 2009! These were taking up a large amount of space. I simply removed both accounts and this recovered approximately 2.5GB which gave enough leeway to work with but did not solve the issue of huge storage being taken up mysteriously as there was still 96GB taken up that was hidden somewhere.

After a great deal of poking around with Spotlight in her hidden user Library I eventually came across some Sky iMap Log files which were responsible for the missing 96GB and about 1.6GB of similar files for 1&1 iMap email. Hand removal of these got back a working and much faster! MacBook.

I have absolutely no idea why or for what reason these supposed gargantuan log files existed. Presumably they should have been deleted but weren't.

Those struggling with high storage usage may find it helpful to look for similar issues with email.

A cautionary tale for those reluctant to delete old un-needed emails.

Hope this helps.

@Gin-Luke is a life saver. I was able to use du utility to investigate what was taking up most of my space.

get the details at command line with: man du

for me its was:

1) ~/Library/Developer/Xcode/iOS DeviceSupport => 20g

2) ~/Library/Developer/Xcode/Archive => 11g

3) ~/Library/Containers/com.docker.docker => 11g

Solved!

Been on the phone today for 1.5 h with a brilliant 😊 Apple Support Consultant who solved the case. Turns out the main problem was a log file in com.apple.mail which continuously kept adding on massive amounts of data

(Note that these are .txt files. We had fun calculating that a 560 GB file would equal about 560 trillion characters...)

So, deleted the log files and turned off log connection activity

...et voilá!

What a relief!

I had this problem, my Mac was showing 417GB in System resources! I had 12GB free on a 500GB HDD which seemed absurd.

Turned out to be a file AAMupdater (if any of you use Adobe Creative Cloud) which was taking up 350gb. I downloaded omnisweeper to find the file and just deleted it. But do your research first as I have yet to see the implications of me deleting this file. Adobe is working fine so not to bothered yet)

Reset my Mac and now it shows I have 348GB Free (from 12GB, not bad)

Good Luck

I found the solution to this issue for my computer. My system storage was around 150gigs, I tried a few ideas like looking for timemachine snapshot but I didn't have any. I cleared out all the large files and still it was 150gigs.

I started doing a "get info" on every folder on my HD. And narrowed it down to /Library/Application Support/Symantec/AntiVirus there was 150 gigs of old scanning data for everyday that the software scanned.

I also found out that some parts of the Symantec app had been moved to my Incompatible Software folder and was no longer opening on startup, must have happened when I upgraded to Sierra. I'm guessing without the software fully running, its scanning and storing the info, but never deleting the old files like it should.

I'll have to have my IT department reinstall and see if it keeps storing all that info or if it starts deleting it again.

I had the same problem too; after a short investigation with specific software (eg: Dr. Cleaner) in my case the space was occupied by bitcoin blockchain, which I used to test it.

After its deletion, I had about 180GB free back again.

I had the same problem. googled about it tried different things, nothing work.

eventually, I decided to reset my MacBook Pro, reinstall the OS, and restore it from Time Machine.

in the restore option, you will see the file and document restore option the did categorized the those miscellaneous files into one check box item, and make sure you don't check that one.

happily using my MacBook Pro now with the received ~100GB

I was having the same problem and just found a solution.

In my case, I had a 250gb hidden folder used by the Mail app filled with what was likely just runaway draft messages. If you use IMAP for a Google or Gmail account, this could be your issue as well.

First, in Mail, delete all the Drafts for that email account. Then, to prevent this in the future, go to the preferences for that account in Mail and change the Mailbox Behavior for Drafts to "On My Mac".

Quit Mail.

Then, use OmniDiskSweeper, free download from the highly reputable OmniGroup, https://www.omnigroup.com/more

After you open from the Finder though. Quit and open it again using Terminal so that it will have permission to look inside hidden folders. In Terminal and type:

sudo /Applications/OmniDiskSweeper.app/Contents/MacOS/OmniDiskSweeper

Then in OmniDiskSweeper, select the drive and click "Sweep"

After the sweep, I was able to drill down through the biggest folders along this path:

[user]/Library/Mail/V5/B83...(long code)/[Gmail].mbox/Drafts.mbox/4D3......(long code)/Data/

Inside that "Data" folder is a set of folders named with a single numeral (e.g., "0"). I think there were nine or ten. And within them, there was 250gb worth of coded files ending in ".emlx" scattered deeply through uncountable more single numeral folders.

To be safe, what I did was open that Data folder in the finder (there's a button in OmniDiskSweeper. Then in the Finder, open each one of the numeral folders which it contained. So I had nine or ten open single numeral folder windows (actually I did it in Finder tabs).

I then selected and trashed the contents of each one of those single numeral folders under Data. Literally millions of .emlx files and their folders.

Once I was done. I re-indexed spotlight via terminal: "sudo mdutil -i on /" waited an hour then restarted. After another hour or two, the Storage graph under About this Mac confirmed it. I had cleared 250gb of space with nothing lost (except maybe some old email drafts).

Hope this helps.