System Data using all my storage

On my iMac Retina 4K 21.5 inch 2019 with an Intel Core i5 and 250GB SSD running Sequoia 15.3.1, System Data is now taking up 140GB which leaves little or no room for anything else. See screen shot of storage.

Is there anything I can do short of buying an iMac with an Apple chip? I've tried using 'Clean my Mac', restarting in safe mode, removing unnecessary files and I use iCloud storage for photos and mail where I pay for 2TB of storage. Is reinstalling everything from a Time Machine back up likely to be worth the stress and effort. Can anyone help with anything effective. When I first noticed the problem a couple of months ago, System Data was around 50GB, it then increased to 110GB and is currently 140GB.

Thanks

John

iMac 21.5″, macOS 15.3

Posted on Feb 20, 2025 3:02 AM

Reply
Question marked as Top-ranking reply

Posted on Feb 20, 2025 3:35 AM

CleanMy Mac was used and will not fix this issue


in fact, it may have made a bad situation even worse


CleanMyMac , aka “ BrickMyMac “ get rid of this application as per the Developers Instruction


Part 1 of 2


System Data: Contains files not listed here. It includes system files like log files, caches, VM files, and runtime resources. Temporary files, fonts, app support files, and plug-ins are also included.


You can’t manage this category’s contents. macOS manages them, and the size varies based on your Mac’s state.


Users have control over the User Account Folder (Home Folder). All other areas are inaccessible.


It’s good computer practice to keep at least 20% to 25% of the total drive capacity empty to avoid unintended consequences.


Purgeable Space is controlled by the operating system. When the system needs more empty space, it moves some purgeable space to empty space.


There’s no user action to hasten this transition. It can take days or longer.


The links below help identify what’s taking up space on the internal drive and provide ways to remove user-controlled data (Home Folder).


Rebuild the Spotlight index on your Mac.


What is “Other” storage on a Mac, and how can I clean it?


Free up storage space on your Mac.


GrandPerspective


How to delete Time Machine snapshots on your Mac.


This often occurs if the Time Machine Drive isn’t attached to the computer and TM Backup is set to run on a schedule.


TM Backup makes snapshots on the internal drive until the Time Machine Drive is attached. Then, the snapshots are transferred to the external drive.


View APFS snapshots in Disk Utility on Mac


See used and available storage space on your Mac.


Locate backups of your iPhone, iPad, and iPod touch.


Delete a user or group on Mac


If you use a suite of Adobe applications on this computer, they may create large cache files that can be removed. However, the Adobe cache files will be recreated as the applications need them.


https://helpx.adobe.com/ca/premiere-pro/kb/clear-cache.html


The same clearing of System Cache files can be achieved by booting into Safe Mode. They will be recreated as the system requires. 


Part 2 of 2


From another contributor @etresoft regarding Free Space and Available Space 


Free vs available disk space huge differe… - Apple Community


Quote >>  “ The "available" storage is the amount of used storage that the operating system could automatically delete if it felt that it was really necessary. The "free" storage is the amount that you can actually use for something.


There are system processes that run in the background and automatically delete some of the "available" storage and convert it to "free". If you completely run out of storage, then those system processes will try a little harder. When you "delete" files you are just hinting to the operating system that you don't need those files anymore. The operating system will eventually remove them, but on its own schedule.


Certain tools will allow you to force the issue and manually clean up some of this storage and manually delete local snapshots. But that is only temporary. "  << End Quote 

1 reply
Question marked as Top-ranking reply

Feb 20, 2025 3:35 AM in response to jraby

CleanMy Mac was used and will not fix this issue


in fact, it may have made a bad situation even worse


CleanMyMac , aka “ BrickMyMac “ get rid of this application as per the Developers Instruction


Part 1 of 2


System Data: Contains files not listed here. It includes system files like log files, caches, VM files, and runtime resources. Temporary files, fonts, app support files, and plug-ins are also included.


You can’t manage this category’s contents. macOS manages them, and the size varies based on your Mac’s state.


Users have control over the User Account Folder (Home Folder). All other areas are inaccessible.


It’s good computer practice to keep at least 20% to 25% of the total drive capacity empty to avoid unintended consequences.


Purgeable Space is controlled by the operating system. When the system needs more empty space, it moves some purgeable space to empty space.


There’s no user action to hasten this transition. It can take days or longer.


The links below help identify what’s taking up space on the internal drive and provide ways to remove user-controlled data (Home Folder).


Rebuild the Spotlight index on your Mac.


What is “Other” storage on a Mac, and how can I clean it?


Free up storage space on your Mac.


GrandPerspective


How to delete Time Machine snapshots on your Mac.


This often occurs if the Time Machine Drive isn’t attached to the computer and TM Backup is set to run on a schedule.


TM Backup makes snapshots on the internal drive until the Time Machine Drive is attached. Then, the snapshots are transferred to the external drive.


View APFS snapshots in Disk Utility on Mac


See used and available storage space on your Mac.


Locate backups of your iPhone, iPad, and iPod touch.


Delete a user or group on Mac


If you use a suite of Adobe applications on this computer, they may create large cache files that can be removed. However, the Adobe cache files will be recreated as the applications need them.


https://helpx.adobe.com/ca/premiere-pro/kb/clear-cache.html


The same clearing of System Cache files can be achieved by booting into Safe Mode. They will be recreated as the system requires. 


Part 2 of 2


From another contributor @etresoft regarding Free Space and Available Space 


Free vs available disk space huge differe… - Apple Community


Quote >>  “ The "available" storage is the amount of used storage that the operating system could automatically delete if it felt that it was really necessary. The "free" storage is the amount that you can actually use for something.


There are system processes that run in the background and automatically delete some of the "available" storage and convert it to "free". If you completely run out of storage, then those system processes will try a little harder. When you "delete" files you are just hinting to the operating system that you don't need those files anymore. The operating system will eventually remove them, but on its own schedule.


Certain tools will allow you to force the issue and manually clean up some of this storage and manually delete local snapshots. But that is only temporary. "  << End Quote 

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System Data using all my storage

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