How can I clear 394GB of system data on MacBook Air running Sonoma 14.7.6?

My son's recently purchased second hand MacBook air has a storage problem. It has 499.96 gb total storage, with 420.26 gb being used of which 394.3 is system data!!

How do I remove some of this, as it is making the machine difficult to use for music and photos.

It is using sonoma 14.7.6.


[Re-Titled by Moderator]

Original Title: Remove system data MacBook air





MacBook Air 13″, macOS 15.5

Posted on Jul 14, 2025 3:40 AM

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Question marked as Top-ranking reply

Posted on Jul 14, 2025 4:21 AM

What to trim down the /System/Volume/Data to a more reasonable size ?


The more  popular and effective ways to address this issue is to Start Over from Scratch 


For Apple Silicon computer >> Use Disk Utility to erase a Mac with Apple silicon.


For Apple Intel computers >>   Use Disk Utility to erase an Intel-based Mac followed by How to reinstall macOS


Always make a Time Machine Backup  before  proceeding 


It is also suggest to  Only Migrating the User Account and nothing more.


Emphasis on User Account Only


Reinstall the Needed and not the Wanted applications from the Apple Apps Store or Directly from the Developers 

3 replies
Question marked as Top-ranking reply

Jul 14, 2025 4:21 AM in response to gary stark

What to trim down the /System/Volume/Data to a more reasonable size ?


The more  popular and effective ways to address this issue is to Start Over from Scratch 


For Apple Silicon computer >> Use Disk Utility to erase a Mac with Apple silicon.


For Apple Intel computers >>   Use Disk Utility to erase an Intel-based Mac followed by How to reinstall macOS


Always make a Time Machine Backup  before  proceeding 


It is also suggest to  Only Migrating the User Account and nothing more.


Emphasis on User Account Only


Reinstall the Needed and not the Wanted applications from the Apple Apps Store or Directly from the Developers 

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How can I clear 394GB of system data on MacBook Air running Sonoma 14.7.6?

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