System Storage Taking Up Way Too Much Space in macOS Sierra

just bought a new MacBook, had the same problem. I took about 80GB worth of music, put it into "my documents", then from there dragged the files into iTunes. I noticed iTunes had about 80GB, and my system storage wasn't far off that, so I deleted one song from my documents, and went to see if it would still play on iTunes. it did. so I deleted all my music files from "my documents", and the music still plays on iTunes, and iTunes still says there is about 80GB of music on there.

I had a back up of my music on an external hard drive so I wasn't too worried about losing my music from the laptops storage... id suggest if anyone deletes their files like I did to have a back up. I've cleared up a lot of space from my "system storage", and the files are still playable in iTunes, almost as if all the music files were stored twice, once in "my documents" and once in iTunes... its different to a PC where the files are stored where you store it and only links are made in iTunes to the music files (saving files only once)....hope this helps a few of you

The fact that the representation of the storage on your hard drive is wildly in error has nothing to do with system performance.

Download and run Etrecheck. Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.

#2

This:

When a file gets deleted without any Time Machine backup, MacOS has a feature of a local Time Machine backup, which saves the file into the System section as shown in the About This Mac> Storage. The purgeable space is saved for whenever a local time machine backup needs to occur if in case any file had been deleted accidently from the system by the user. There is a way to disable this local time machine backup. Here are the following steps:

1. Open terminal
2. Type "df -h". This will show you a volume of MobileBackups if it was enabled and if this does apply to your system.
3. To disable your Mobile Backup, type "sudo tmutil disablelocal". When prompted for password then type in your password.
4. Check your Storage and see that the purgeable space has been deleted plus the System section has also shrunk to just contain the OSX.

To enable/re-enable the local Time machine backup:

1. Open Terminal
2. Type "sudo tmutil enablelocal". When prompted for password then type in your password. This will then start making a local time machine backup in the system. This will take a while. If you want a quick backup then type "tmutil snapshot".
3. Check your Storage to see that the backup has been made with minimal amount of purgeable space since the snapshot was made. Note that the system section has also increased at this point too to include the previous backup but this time without the space for the purgeable space reserved for this size.

This turned out to be from core files on my system.

If it happens to you, delete files from /core:

# Remove core files

sudo rm /core/*

Enter your password if prompted.

It is safe to delete these core files: they are copies of the memory from programs that crashed. They are useful for developers to debug issues.

For good measure, also add the following to your .bashrc or equivalent:

# Limit core files to 10 MB at most

ulimit -c 10000000

Very serious problem indeed!

My system storage jumped from approximately 30GB to 75GB. I was clearing some space in iTunes and other useless app and everything became untouchable system files!

I might have been able to solve the issue by going to ~/Library/caches using Go To Folder and deleting the cache files that were created today, as I was clearing space in my MAC.

Weird stuff, took the best part of my day from me!

if anyone is having this issue follow the instructions on this youtube video in short it's your time machine back up that is taking up all that room now

How to Clear System Storage on MacOS High Sierra - YouTube

*FIXED*

Hi! I have found a way to fix your problem! Some applications or folders in your MacBook library are more storage-consuming than they look. I had Steam Engine installed on my MacBook which surprisingly took 21 GB of my storage up. You can solve this problem by downloading the OmniDiskSweeper [Free Download Here] and [Tutorial Video Here]. Make sure you don't delete the important files in the library folder (or your MacBook won't run properly). If the application is used correctly, it should free up 40% of your disk.

I had the same problem and after trying endless solutions, including all of the ones posted in this thread (p.s. thanks to everyone across all the threads trying to help solve this problem), and ultimately the only thing that worked was doing a clean install of the new OS.

In case you're still searching for an answer, or in case someone else with this problem comes upon this thread, I posted a more detailed update regarding what ultimately worked over in my thread regarding this hidden space / system storage problem; Re: Cannot find or remove 100+GB of "Hidden Space

Hopefully that helps anyone who hasn't been able to solve this yet with some of the other available solutions.

This was my problem.

https://discussions.apple.com/thread/7683120?answerId=32683243022#32683243022

Read through 11 pages of replies that basically solved nothing or wanted me to install freemium crap apps. I had over 200GB of .txt log files from Apple Mail logging connections. Are you kidding me!?!? This just kept filling up my drive and filling up my drive. The more I cleaned out files the worse it got.

Apple you can't have a log file take the system down. Please put some kind of limit in place.

I turned off connection logging in Apple Mail and cleaned out the log files. Problem solved.

I have been researching this issue because i also have it, I have found the best solution to the problem which is to use OmniDiskSweeper, the app allows you to see what is taking up all of the space on your MacBook and allows you to delete it straight away. Here is the link to the website to download the app: https://www.omnigroup.com/more , i hope that all of you can fix the problem using my solution because it worked for me and is easy to operate.

There is also a video tutorial here for all of you. :) enjoy!

Don't rely on that method to get the actual size of the system folder. I get 31 GB as my system size but the folder itself is only 13 GB when selecting it and using the Get Info on it.

but the folder itself is only 13 GB when selecting it and using Get Info on it.

The method with the higher number is known to be either very inefficient or includes files elsewhere on the hard drive that are associated with the system.

So when you want to know sizes use the Get Info method.

Too all the people who tell us to ignore the problem. It’s not just that it looks that the disk is full. With my MacBook working got a pain in the *** and slow, almost impossible to work with .. as if the ssd is almost full. So there has to be more to it.. what helped for me at the end is going back to a time machine backup befor the update to macOS High Sierra.. and now I’m waiting..

By default, that would be where your stuff gets stored. On some newer versions, you have an option to look for large files that you might want to delete. If you are showing the hard drive on the left side on the finder (probably named something like Macintosh HD) you can right-click it and select "Manage Storage". The dialog that comes up will show the different areas like Documents. Click on Documents or messages or whatever folder is of interest, and it will show you the large files. Another way to get to this tool is to click the apple in the top left of the screen and select "About This Mac", then in the dialog that pops up, click Storage on the top of the dialog and then click the button "Manage"

I found that iCloud drive was taking 600GB of space on my iMac. I deleted that then located the iCloud Drive Archive folder, deleted that and my mac System storage lowers significantly and my iMac started to get a lot faster again as well.