User profile for user: appppppppppppleeeeee
appppppppppppleeeeee Author
User level: Level 1
4 points

How to locate and delete 100 GB of hidden System Data on MacBook Air running Sequoia 15.4.1?

Hello,

I do love Apple, but unfortunately I am encountering a strange system storage bug on my MacBook Air M1 MacOs Sequoia 15.4.1


Before posting this issue I have gone through a lot of apple forum threads, reddit posts on this topic, googled days, tried OnyX and OmniDiskSweeper and Apple's own Utility Disk Manager, and deleted manually Cache files, Apple Logs etc. - Nothing actually worked :-(


As you can see on the screenshot, the GB calculation does not add up and I am unable to locate the ca. 100 GB which are causing the system data to increase.


I noticed similar problems on my iPad and iPhone, so I am not even sure where to post this question, my only guess is, that it always happens when you transfer large video files from an Apple device onto an external storage.


Any suggestion or hint would be very helpful. Thank you very much and thanks for your patience :-)




[Re-Titled by Moderator]

MacBook Air 13″, macOS 15.4

Posted on Apr 29, 2025 12:56 PM

Reply
3 replies
Sort By: 
User profile for user: Ronasara
Ronasara
User level: Level 6
15,387 points

Apr 29, 2025 1:30 PM in response to appppppppppppleeeeee

The Other Category, or system data, can not be altered, modified, move or deleted since it is part of the Mac’s operating system. Doing so would corrupt the OS and render the OS inoperative requiring a Wipe and Re-Installation.

The Other category is a potpourri of files which include:

• System temporary files

• macOS system folders

• Archives and disk images (.zip, .iso, etc. - often found in the Downloads folder)

• Personal user data

• Files from the user’s library (Application Support, iCloud files, screensavers, etc.)

• Cache files

• Fonts, plugins, extensions

• Other files that are not recognized by a Spotlight search

• Media files that cannot be classified by Spotlight as a media file because they are located inside of a package

They can be located anywhere on your hard drive. The files that you have control over are located in the Documents, Downloads, Pictures, Music and Movies folders.

If your HD is becoming too full this may be a good time to consider adding an external drive for storage. Then you can move files onto it and then delete them from your HD to clear needed space. Easy to do and problem solved.

Reply
User profile for user: appppppppppppleeeeee
appppppppppppleeeeee Author
User level: Level 1
4 points

Apr 29, 2025 1:40 PM in response to Ronasara

Hi Ronasera,

thank you very much for your reply. I usually do so. In your opinion is it possible that the System caches some of the large files I copied yesterday to external Harddrive?

As already said, I experienced the same on iPhone and iPad, I delete everything on the devices, but the system data remained. Thanks :-)

Reply
User profile for user: Ronasara
Ronasara
User level: Level 6
15,387 points

Apr 29, 2025 2:13 PM in response to appppppppppppleeeeee

I am not an expert but system data is located in various areas of the Mac. It is possible to reduce it somewhat but it will not make a significant difference in the total. If you do a restart in the Safe Mode it will clean the Mac's caches. Hold down the Shift Key on startup. This can take several minuted while the computer cleans its caches and does repairs to the OS. Then you can restart normally. Also, when some apps are removed bad ragging them to the Trash, some will leave bits scattered throughout the computer. Better to use a vendor's uninstaller if one is available. It will remove everything.

Reply

How to locate and delete 100 GB of hidden System Data on MacBook Air running Sequoia 15.4.1?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.
Learn more Sign up