MacOS Sierra - 50-100GB of system storage??

The system is not actually taking up that much storage. It is actually miscategorized. To see if the system is truly taking up that much space:

-go to finder

-select go at the top of the screen

-go to computer

-select "Macintosh HD" (or whatever you have named your Hard Drive)

-command a - select all

-command i - get info on all folders

After the information loads in the top right of each box will be a GB amount. Normally it is the user folder that is taking up all the space. And you have to clean it out.

120 GB of SSD storage doesn't do the job. What you need is 10x that amount of storage and way more memory to have a working machine. Got a bigger HD or better get a new machine and couple hard drives connected outside of your little computer.

How is this answering the question ? I've been using a 120 Gb SSD throughout my macOS experience and it always DID the work just fine. Also, how would you explain why almost every entry-level Apple MacBooks comes with a 128 Gb SSD ? This is neither helpful nor accurate.

I thought found a solution. Yesterday I upgraded to the Beta high Sierra, like you I had 100gb on "system"... but I was also getting annoyed by the computer asking for the keychain password every 3 seconds.

I created a new user account and completely deleted the older one. It helped the keychain issue but not the "system" folder thing... anyone has a solution?

You should also consider checking if you have backed up other apple devices to your Mac. I have seen cases where users have backed up multiple iphones and Ipads to their and these can definitely eat up lot of system space.

Do not launch OmniDiskSweeper, use Terminal to run as root. This will get files in system not just Users folder

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

command period to quit

Do not launch OmniDiskSweeper, use Terminal to run as root. This will get files in system not just Users folder

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

Use command period to quit

It's possible the hidden files are Time Machine backups. Starting with High Sierra, even a desktop Mac creates local snapshots.

How local snapshots use storage space

Time Machine in macOS High Sierra stores snapshots on every APFS-formatted, all-flash storage device in your Mac or directly connected to your Mac. Time Machine in earlier macOS versions stores snapshots only on the internal startup disk of Mac notebook computers.

To make sure that you have storage space when you need it, snapshots are stored only on disks that have plenty of free space. When storage space gets low, snapshots are automatically deleted, starting with the oldest. That's why Finder and Get Info windows don't include local snapshots in their calculations of the storage space available on a disk.

Published Date:Sep 26, 2017

To find all the local timemachine snapshots. Enter this command in the Terminal:

tmutil listlocalsnapshots /

Delete them one by one using

tmutil deletelocalsnapshots <snapshot_date>

This "feature" with APFS + TimeMachine local snapshot is very annoying as time machine will cache whatever you dump into your computer locally on your machine. If you dump 300GB files on your desktop, it WILL cache it in the local snapshot. And it will stay on your computer even after you delete the original file. Yes, you just lost 300GB space even you have already delete the original file.

You will have to manually delete the local snapshot in TimeMachine to get back your space."

https://forums.macrumors.com/threads/high-sierra-wouldnt-remove-320gb-purgeable- space-please-help.2077666/#post-25222356

120 GB of SSD storage doesn't do the job. What you need is 10x that amount of storage and way more memory to have a working machine. Got a bigger HD or better get a new machine and couple hard drives connected outside of your little computer.

Just checked my iMac and the System folder is 7.84Gb, Library folder is 4.88Gb and Applications folder is 7.99Gb - that's a total of approximately 21Gb all under Macintosh HD.

With all my other stuff, music, photos, documents etc the total is only 100Gb, still have 400Gb available! - so would say your usage appears rather high. Only thought is the upgrade process sometimes moves files into a folder that it deems not compatible with the new system and secondly sometimes Finder does not always report usage accurately - you could try booting into Safe Mode (hold the shift down on restart) and then when that's done boot back normally and see if that recovers some lost disc space.

Where do you see how much storage is taken up by System?

I saw this reported on another forum.

Thanks guys, went and got DiskInventoryX and found out it was Xcode simulators taking all that space.

Personally, I like OmniDiskSweeper to find large files.

http://www.omnigroup.com/products/omnidisksweeper/

Did you figure this out? I have the same issue with my early-2015 Air. 100GB on system storage.

This discussion might be useful for a few ideas if you haven't already viewed - Why does the system use 150 GB of storage?

Hi petey2428,

I just checked mine and system takes 108 G of storage.

I guess it is because that Mac counts all the files with unknown extension as "system" (anyone please correct me if this is wrong).

I have these video game support files with extensions of ".001" ".002"..., and they won't be found under "system information".

In a word, I don't feel that there are some sort of problems with your system. You might want to check if you have these kind of supporting files, some of them might be taking much of your storage.

These are mine:

dianeoforegon, you have the right idea.

listen everyone, i had this issue today 12/28/16 where i know i had 350Gb of free space and i was getting the system storage almost full message. I installed omnidisksweeper and i quickly saw there was a log file that was in my case associated with parallels that was 350Gb in size. I deleted the file and emptied the trash. problem solved.
as for what caused the log file to report at that size i'm not sure but I will continue to monitor.