macOS High Sierra – Huge System Storage

I cut and pasted the commands given below in Terminal... worked perfectly. Thank you. Took my system memory down from 340GB to 22GB.

Question. Does this affect Time Machine's ability to restore from backed up files?

What is the code you typed? I hope you remembered to change the name of the code how your backup was saved in your system.

I got it wrong, the 1st time and then found out by intuit that I needed to change it. Then it worked.

@Yairkauf

Try rebooting your computer and pressing and holding all the following at the same time CMD + OPT + ”P” + “R” before the Apple logo release after you hear the Apple chime twice, then let it boot up.

This clears the random memory (RAM) which could potentially be throwing your reading to an older result.

Else try this step again but refresh the SMC. (Shift + CMD + OPT)

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 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.

I had this problem and Apple Support spent weeks on it and didn't get anywhere. I didn't have a problem with time machine files at all and was facing a complete reinstall when I came across a thread on another site. Someone there suggested unmounting any unused volumes that had not been ejected properly. (I did it a long-winded way, but someone else suggested the following is the way to do it correctly:
diskutil unmount /Volumes/Untitled.

Unmounting the volumes solved the problem for me instantly and it hasn't come back.

Thanks for sharing and I'm glad you resolved your issue. Regret that I'm not savvy enough to do the same by myself on Terminal with your post. Perhaps you could go through a step-by-step description of how to find and unmount/uninstall a disk volume or multiple disk volumes?

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.

This has been happening to me for months now. Had a workaround because nothing actually fixes the issue ... I have been restarting, and the system file allocation goes back to normal. Today, I installed the new update to High Sierra and the issue is actually amplified! I Am going back to El Capitan because apple doesn’t seem to have a solution or even acknowledge that there is one. Hours of time with support and have already done about 10 clean installs and have wiped and started from scratch twice. I give up.

Probably a bit late but it seems like everyone has different problems, so thought I'd add what mine was, might help someone. I use Xcode a lot to build versions of the apps I'm testing in work. Each build added to the System Storage. I went to Users > <kramnadroj> > Library > Developer > Xcode and deleted everything from within the folder iOS DeviceSupport. There were loads of folders named after each iOS build (e.g. 11.2.1, etc.). Deleting all these freed up my storage from 90GB to 20GB. Hope this helps someone.

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.

High sierra is a huge "cloud sync" os, but cloud actually means cached locally,

in the finder click Go, hold down the option key and you will see Library appear, go into library and look for a folder called Caches, command J and select calculate all sizes, give it a few mins to get the sizes of the directory,

if its large (normal size is 1-3gb) download and run onyx from titanium software, its free, and will clean you right up safely. install it ,go to "cleaning" , then the "user" tab, and select Execute. takes a few mins, then reboot. your good to go,

you can go through the other options of system/internet/fonts/logs/etc and let it clean you back up to a working fast Apple again. theres also a maintenance tab that allows you to clean things up a little further. and its safe, trusted and free, heres a link to the source page, choose the version for your OS version.

https://www.titanium-software.fr/en/onyx.html

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 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.

I have spoken to Apple support about this before. DO NOT TO ATTEMPT TO DELETE SYSTEM FILES. You run a risk of breaking something important.

From what I understand, the most likely reason for this is local time machine backup snapshots. You are best to ignore it, and from what I have heard if your storage gets full, your Mac should begin to delete unnecessary files.

I know it seems worrying, but try to ignore it until it becomes a problem. I have a 128gb MacBook, and it concerned me when system took up 40GB!!

try to ignore it for now, sorry for lack of a more definitive answer but I personally believe this is a better idea than trying to input lines of code from random websites on the internet in the hope of doing something!

hope this helps!