Huge System Data Filling Storage on Your Mac? 7 Possible Fixes

Many Mac users are reporting that “System Data” is taking up huge amounts of disk storage capacity on their Macs. While this issue is reported more commonly with MacOS Sequoia, some users find the bloated System Data storage on older versions of MacOS as well. In many cases, the “System Data” in MacOS is taking up unusually large amounts of disk storage, with reports ranging in size from 100GB to even 500GB. With how small the SSD storage capacity is on Mac’s and how much of a huge premium Apple charges to have more local storage, something consuming such a large amount of disk capacity is understandably frustrating and concerning. Even if you have an upgraded 1TB drive, having “System Data” take up 100GB to 500GB of that is obviously unreasonable and ridiculous.

Not everyone reports having an inordinately large “System Data” folder in macOS. In fact, many users have System Data that takes up a reasonable amount of storage, around a few GB to perhaps 10 or 20GB. This article is intended to address the Mac users who have excessively large “System Data” capacities on their Mac, and offer a discussion and some solutions around the problem.

Potential Fixes for Large “System Data” on Mac

Here are a list of some potential fixes that users have reported for remedying the excessively large “System Data” issue on MacOS:

• Restart the Mac
• Boot into Safe Mode, then reboot back into normal macOS
• Install any available MacOS system software update
• Backup the Mac with Time Machine and let the backup complete
• Backup, format, reinstall MacOS, restore from backup – huge hassle but multiple reports of this working
• Clearing out local caches, clearing Spotlight caches, and removing local iOS/iPadOS backups
• Using fewer Safari tabs, closing tons of open Safari tabs if applicable – presumably Safari tabs quickly consume available RAM and then start swapping, leading to caching and disk usage of swap files in /System/Volumes/VM/

Sometimes a simple restart fixes the problem. Sometimes a restart of MacOS does nothing for the problem. Sometimes installing system software updates resolves the issue, whereas sometimes installing system software updates makes the issue worse or return if it was resolved.

A fair number of users have reported that rebooting the Mac into Safe Mode, then rebooting yet again, will remedy the issue, but that it will return. For example, here’s a positive report of this approach from Apple support forums:

“I’m having this problem too! I spent an hour plus on the phone with Apple Tech Support last month. The fix we stumbled upon was to boot into Safe Mode. After booting into Safe Mode, my System Data shrunk from 365GB to 45GBs. I switched my Time Machine backup schedule from daily to weekly thinking that was the culprit, but I’m still having to boot into Safe Mode every 1-2 weeks to shrink my System Data.”

My “System Data” folder ballooned out to 100GB after installing MacOS Sequoia 15.5 update and no matter what I do I have not been able to recover that storage capacity. Reboots, safe mode reboots, installing updates, cache clearing, deleting old backups, using third party cleaner apps (many of which are scams and to avoid), you name it, and that 112GB of “System Data” storage will simply not budge.

Why is “System Data” so large on the Mac?

It’s not always clear why “System Data” on MacOS can be so enormously large.

Sometimes the bloated System Data problem is related to large system caches and temporary files, including bloated CoreSpotlight Metadata storage and large com.apple.mediaanalysisd caches, and while you can clear caches manually and that might help the problem, it doesn’t always remedy the excessive storage consumption of “System Data”.

Some users report that “System Data” increases in correlation to the size of files they send to the Trash and attempt to delete in MacOS Sequoia. Other users report that “System Data” seems to increase exponentially after they have backed up an iPhone or iPad to their Mac. There’s not always

Is huge “System Data” unique to MacOS Sequoia?

The bloated “System Data” in MacOS is commonly reported with MacOS Sequoia in particular, so there may simply be a bug relating to System Data on the Mac that has not been resolved in any version of MacOS Sequoia up to this point. With that said, there are Mac users with earlier versions of system software who also report having large System Data allocations.

It’s worth remembering this is not a unique problem to the Mac and MacOS, and an age-old problem for iPhone/iOS and iPad/iPadOS is their “System Data” and “Other” storage can also balloon into intrusively large sizes that take up tons of storage capacity on those devices too. What is unique however is that, despite having access to the file system in MacOS, it’s still very difficult to track down and resolve the bloated System Data folder problem in MacOS.

search on Apple Support forums for “System Data” returns over 9000 results, and the
Apple forums,support, and discussions along with MacRumors forums and reddit also contain many such complaints. Nobody has a clear answer to the cause, and nobody has a clear solution either. One frustrated user reports having 68% of their 1TB drive taken up by System Data; “I have an open support case with Apple on this. I have spent countless hours on this and up to this point, over three hours on the phone with them trying to figure out what is going on. I have run several rounds of diagnostics and provided the output to them which hopefully will reveal root cause.
My scenario is my 1TB drive has 680GB being eaten up by system files.”

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Have you experienced any problems with MacOS “System Data” taking up an unusually large amount of storage on your Mac? Did this only happen for you with MacOS Sequoia or did you experience it with another MacOS version? Did you find a solution to this issue? Did any of the suggested fixes here work for you? Share your experiences and thoughts in the comments.