User level: Level 1 (4 points)How come my "System Data" usage is 60GBs? I thought it would occupy at most a dozen GBs. What are some fixes for this?
edit: Needless to say, I tried to reinstall 27.0 hoping it would fix it, but no results.
Posted on Oct 26, 2026 7:00 AM
User level: Level 9 (72,871 points)Oct 26, 2026 7:03 AM in response to fscelzo18
You should aim to have 15-20% of your total internal storage as free space (~30-40 GB as an absolute minimum). If you do not have enough free space on your Mac’s internal storage, then here are some steps to take to safely free up space:
Free up storage space on Mac - Apple Support
Optimize storage space on your Mac - Apple Support
How to free up ‘System Data’ and other st… - Apple Community
"System Data" comprises your data, but they are typically hidden files that Spotlight cannot assign to a specific category like Documents or Applications. Examples include Outlook attachments, iOS updates, Cloud storage caches, etc. Starting with macOS 27 Golden Gate, System Data also includes what macOS used to call ‘purgeable’ storage – system caches, Time Machine snapshots and some other data, though the user had no control over the purging. Trying to manually clean out hidden files in System Data is likely to cause more problems than it solves, macOS hides those files for a good reason. Follow the steps in the linked articles above.
On macOS 27, separate ‘purgeable’ space is no longer reported, and instead those data are now considered as used space. They are also now included in System Data, accounting for the apparent increase you (and others) have noticed. You didn't lose space, macOS just categorizes things differently now than on Tahoe.
More detail on this change in this User Tip:
System Data and Free Space Changes in Gol… - Apple Community
The best advice is to just ignore the System Data category. ‘System Data’ is merely a catch-all category for files that Spotlight cannot assign to specific categories like Applications, Documents, Photos, etc. In fact, what is now shown as System Data used to be reported as ‘Other’, Apple changed the label in macOS 12 Monterey. System Data probably sounds better, but Other was closer to reality.
User level: Level 10 (123,805 points)Oct 26, 2026 7:39 AM in response to fscelzo18
System Data taking up a large amount of storage is a common question on Mac.
There is no single setting that simply “clears” System Data because this category can include a variety of files, including caches, logs, temporary files, and APFS snapshots.
If you want the most comprehensive solution, back up first, erase the Mac, and reinstall macOS.
For Apple silicon Macs, use Erase All Content and Settings.
This removes your data, settings, and applications while leaving the currently installed version of macOS in place and untouched
Make a current Time Machine backup before erasing anything. Apple: Back up your Mac with Time Machine
Afterward, use Migration Assistant to transfer your user account rather than the entire old system, and reinstall only the applications you actually need.
If you do not want to erase the Mac, first determine what is actually consuming the space. DaisyDisk can provide a clearer view of storage usage, and Apple documents how to view APFS snapshots in Disk Utility.
The following Apple Community discussions document additional approaches. Results can vary depending on what is responsible for the storage usage:
Also consider moving large personal files—particularly Photos, videos, music, and other files you control—to an external SSD.
This is often a more appropriate way to free internal storage than attempting to delete files that macOS manages as System Data.
User level: Level 9 (60,836 points)Oct 26, 2026 10:39 AM in response to fscelzo18
fscelzo18 wrote:
How come my "System Data" usage is 60GBs?
60 GB is actually pretty good.
Needless to say, I tried to reinstall 27.0 hoping it would fix it, but no results.
Ha! Does it ever?
The primarily problem here is that you're mentioning "System Data". The only place you could have found that is the System Settings > General > Storage display. "System Data" doesn't exist anywhere else. And I mean that literally, it literally doesn't exist. That Storage display is very confusing and often wildly inaccurate.
It's better to focus on material issues. How much free storage do you have? That alone can be difficult to find as most places in the system will tell you about "Available" storage, which, as you might guess, doesn't actually exist.
But if you run Disk Utility. Go to the View menu and show all devices. Then look at the top level "container" device under APPLE SSD, it will show you your true free storage. It may be the same as the value you see for "available" storage. That doesn't mean anything. Only the "free" value is reliable and has any actual meaning.
Ideally, keep 100 GB of free storage. In a worst-case scenario, maybe you can get away with 50 GB. "Why so much?" you ask? Well, when (not if) the operating system goes haywire and starts consuming all of your storage, 100 GB gives you more time to notice it and prevent data corruption and/or catastrophic failure.
User level: Level 10 (123,805 points)Oct 26, 2026 7:52 AM in response to fscelzo18
Follow on to my previous post and picking up on your " I tried to reinstall 27.0 hoping it would fix it, but no results. "
Reinstall macOS without erasing
It will Preserves your data
This is what you normally do by starting in macOS Recovery and selecting Reinstall macOS without first erasing the disk.
It does not intentionally clear your accumulated application data, caches, backups or all local snapshots.
It may not have helped your 60 GB: if the space is in your Data volume, app data, or APFS snapshots, reinstalling the operating system can leave the cause untouched.
Originally posted at discussions.apple.com/thread/256383228