Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

How to reduce 'System Data' usage on Mac mini M1 for more internal SSD space?

Adam1988

Adam1988

macrumors regular
Original poster
Mar 15, 2013
136
4
United States in Texas, After this will be Japan.
WHAT ARE THE WAYS TO REMOVE THAT DATA?

AT LEAST I KNOW THAT MAC OS IS ABOUT 33.54GB AND MY SHARED INFORMATION IS ABOUT 1.22GB BECAUSE I DON'T SHARE ANYTHING WITH ANYONE I ONLY USE THIS OPERATING SYSTEM FOR MYSELF.

ANYWAYS, I HAVE TRIED EVERYTHING AND EVERY SINGLE LITTLE DETAIL ONTO THE SYSTEM BUT YET NOTHING SEEMS TO REMOVE THAT LARGE FILE SYSTEM DATA CONTAINER OR WHATEVER IT IS. 310.21 GB

SO MY QUESTION IS... DOES THIS DISAPPEAR WHEN YOU UPDATE TO THE NEW MAC OS? OR IT CARRIES OVER?

I AM TRYING TO HAVE MORE SPACE ON MY INTERNAL SSD.

MAC MINI M1 2TB INTERNAL STORAGE (MANUFACTURE SSD CAPACITY)

USED 1.21TB / FREE SPACE 784.51GB + 310.21 GB OF USELESS USE OF STORAGE CAN GIVE ME 905.28GB OF USE. WHICH WILL REST 1094.72 GB OF FREE SPACE...

PLEASE CAN ANYONE HELP ME?! 😭

THANK YOU SO MUCH!

Screenshot 2025-08-12 at 8.20.17 PM.png
 
  • Sad
Reactions: razmanugget
That's how macOS file system works. If applications put files outside their assigned location/folders, macOS will categorise all those files under "System Data".

I would recommened to use application like GrandPerspective to scan the entire disk, find large, unused and safe-to-delete files.
 
  • Like
Reactions: racerhomie, schnaps and Adam1988
I'm not reading a screed of upper case, so don't know the specifics of your problem, but to add to @bogdanw's answer: if you are comfortable with the command line, then ncdu – available via homebrew, etc. – is a great tool for discovering file-space usage.

It might also be worth checking Time Machine local snapshots:
> tmutil listlocalsnapshots /Volumes/Your SSD Name
They're supposed to delete automatically after some time, but I found they just hung around forever, so I delete them after creation – which does raise questions about their usefulness.
 
  • Like
Reactions: IJustWannaTalk, russell_314, razmanugget and 2 others
auxbuss said:
I'm not reading a screed of upper case, so don't know the specifics of your problem, but to add to @bogdanw's answer: if you are comfortable with the command line, then ncdu – available via homebrew, etc. – is a great tool for discovering file-space usage.

It might also be worth checking Time Machine local snapshots:
> tmutil listlocalsnapshots /Volumes/Your SSD Name
They're supposed to delete automatically after some time, but I found they just hung around forever, so I delete them after creation – which does raise questions about their usefulness.
Click to expand...
Oh i am sorry about the thread is cause caps seems to be more bigger font i completely forgot about the tools in the body of the paragraph but definitely will look into the command line i am exhausted right now but tomorrow for sure i will investigate your links. Its cause i had some issues with streamlabs 😭
 
Fishrrman said:
Do you use time machine?
Could some of that "used up space" be "snapshots" ?
Click to expand...
YES! I DEFINITELY DO!

I use time machine in my internal and external drives.
It backs up every hour for whatever reason it may be.

It has helped me so much and im glad that time machine is a life saver!

What are Snapshots!? sorry i am not sure what that is. I don't know if a Snapshot is a backup that is done every hour? or it means something else? or maybe its something its used as a slang in the technology world from apple.

Anyways thank you very much!
 
baconcat_8964 said:
That's how macOS file system works. If applications put files outside their assigned location/folders, macOS will categorise all those files under "System Data".

I would recommened to use application like GrandPerspective to scan the entire disk, find large, unused and safe-to-delete files.
Click to expand...
Thank you! i just download it ! :)
 
auxbuss said:
I'm not reading a screed of upper case, so don't know the specifics of your problem, but to add to @bogdanw's answer: if you are comfortable with the command line, then ncdu – available via homebrew, etc. – is a great tool for discovering file-space usage.

It might also be worth checking Time Machine local snapshots:
> tmutil listlocalsnapshots /Volumes/Your SSD Name
They're supposed to delete automatically after some time, but I found they just hung around forever, so I delete them after creation – which does raise questions about their usefulness.
Click to expand...
I want to learn more about the terminal commands the only issue is that i do not understand what those codes stand for or what they do.

i will conduct a research about it thank you!
 
OP wrote:
"I use time machine in my internal and external drives.
It backs up every hour for whatever reason it may be."

Try this:
Open disk utility.
Go to the View menu.
See if there is a choice named "show APFS snapshots" (name may not be exactly that)
Now, look towards the bottom of the disk utility window.
It should show you snapshots related to tm.
Are there many of them?

If there ARE, I suggest you delete them.
Perhaps every one except the most recent.
Reboot.
Then check your "used up" space again.

Get back to us with your findings.
 
Last edited:
  • Like
Reactions: Adam1988 and auxbuss
I'm perhaps veering off-topic, but does anyone have a good technical write-up of what Time Machine local snapshots actually do?

Apple's own page on it is nonsense: https://support.apple.com/en-us/102154

For example:
Time Machine saves one snapshot of your startup disk approximately every hour, and keeps it for 24 hours. It keeps an additional snapshot of your last successful Time Machine backup until space is needed. And in macOS High Sierra or later, another snapshot is saved before installing any macOS update.
Click to expand...
And:
You don't need to think about how much storage space local snapshots are using, because they don't use the space needed for tasks like downloading files, copying files, or installing new software.
Click to expand...
Yes they do! So I will worry my pretty little head about them, so there!

And:
Your Mac counts the space used by snapshots as available storage.
Click to expand...
… providing you use Apple's magical tools, which add it back for you to complete the illusion. For heaven's sake!

But yeah, other than that: what use are they?
 
  • Like
Reactions: Adam1988
Fishrrman said:
OP wrote:
"I use time machine in my internal and external drives.
It backs up every hour for whatever reason it may be."

Try this:
Open disk utility.
Go to the View menu.
See if there is a choice named "show APFS snapshots" (name may not be exactly that)
Now, look towards the bottom of the disk utility window.
It should show you snapshots related to tm.
Are there many of them?

If there ARE, I suggest you delete them.
Perhaps every one except the most recent.
Reboot.
Then check your "used up" space again.

Get back to us with your findings.
Click to expand...
Thank you! I will definitely do this!
 
auxbuss said:
I'm perhaps veering off-topic, but does anyone have a good technical write-up of what Time Machine local snapshots actually do?

Apple's own page on it is nonsense: https://support.apple.com/en-us/102154

For example:

And:

Yes they do! So I will worry my pretty little head about them, so there!

And:

… providing you use Apple's magical tools, which add it back for you to complete the illusion. For heaven's sake!

But yeah, other than that: what use are they?
Click to expand...
Interesting! Well then they do actually take space! Lol sometimes i dont understand apple lol.
 
auxbuss said:
I'm perhaps veering off-topic, but does anyone have a good technical write-up of what Time Machine local snapshots actually do?
Click to expand...
eclecticlight.co

Understanding and managing Time Machine snapshots

Why Time Machine makes snapshots, and how they can grow and apparently consume free space. What you can and should do to manage this.
eclecticlight.co eclecticlight.co

eclecticlight.co

Time Machine and snapshots

Time Machine has been using snapshots since High Sierra. How can it then use them to make backups to APFS volumes in Big Sur?
eclecticlight.co eclecticlight.co

eclecticlight.co

Managing snapshots: how to stop them eating free space

Snapshots are of great value, but can grow large if you don’t keep an eye on them. If you find Time Machine or another backup utility is storing large snapshots, here’s what to do.
eclecticlight.co eclecticlight.co
 
  • Like
Reactions: Adam1988
baconcat_8964 said:
eclecticlight.co

Understanding and managing Time Machine snapshots

Why Time Machine makes snapshots, and how they can grow and apparently consume free space. What you can and should do to manage this.
eclecticlight.co eclecticlight.co

eclecticlight.co

Time Machine and snapshots

Time Machine has been using snapshots since High Sierra. How can it then use them to make backups to APFS volumes in Big Sur?
eclecticlight.co eclecticlight.co

eclecticlight.co

Managing snapshots: how to stop them eating free space

Snapshots are of great value, but can grow large if you don’t keep an eye on them. If you find Time Machine or another backup utility is storing large snapshots, here’s what to do.
eclecticlight.co eclecticlight.co
Click to expand...
I am extremely clueless about it bro all i know is that they get you back to the place you were before
 
Adam1988 said:
What is reindex? I dont know how to code.😢😢😢
Click to expand...
It forces Spotlight to run an index of all your files and deletes things that you've deleted from the trash that have become stuck. You don't need to know how to code - I don't - just open Terminal when you're logged in as a user with admin privileges (prob your normal one) & paste in;

sudo mdutil -a -i off

to turn it off

sudo mdutil -a -i on

to turn it back on again.

Leave it about 30mins from turning off before turning back on, keep the screen on & it'll force the a search of everything on your computer & puts things back to normal, works especially well if you've just deleted some big files or things look large with system data.

If this doesn't work then the problem will be elsewhere like Time Machine snapshots.
 
  • Like
Reactions: Adam1988
McScooby said:
It forces Spotlight to run an index of all your files and deletes things that you've deleted from the trash that have become stuck. You don't need to know how to code - I don't - just open Terminal when you're logged in as a user with admin privileges (prob your normal one) & paste in;

sudo mdutil -a -i off

to turn it off

sudo mdutil -a -i on

to turn it back on again.

Leave it about 30mins from turning off before turning back on, keep the screen on & it'll force the a search of everything on your computer & puts things back to normal, works especially well if you've just deleted some big files or things look large with system data.

If this doesn't work then the problem will be elsewhere like Time Machine snapshots.
Click to expand...
Oh nice then i will investigate this because its very interesting going deep into the system. Thanks! I thought i had to learn coding or something on the terminal
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back