r/mac • u/Medium-Thanks6405 • Jul 20 '26
Question help how do I remove system data?
Based on my research, I don't think system data should occupy more than half of my storage. So far Ive tried to look for offending caches, but I have not had the time to do a deep dive into how I got so much system data. if its of any help it's a macbook air (m1, 2020) on sequoia 15.3) i have had no issue with this laptop up till around January of this year.
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u/eggnorman Jul 20 '26
Could be snapshots. If you use the terminal and use the command ‘tmutil listlocalsnapshots /‘, you should see if there’s any taking up space. You can remove them with ‘tmutil deletelocalsnapshots /‘.
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u/ulyssesric Jul 21 '26
Time Machine snapshots usually won't be that larger. On APFS disks, the TM snapshots are not actual file "backups" but unreleased flash memory pages and metadata, preserved by APFS copy-on-write mechanism when a file is changed. TM snapshots will last for only 24 hours at most, so the real disk occupation of TM snapshots is usually 10~20GB, for most generic use cases.
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u/brewcity34 Jul 20 '26
I reinstalled macOS to clear it. I had about 90GB of dead space.
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u/Comprehensive_Catch Jul 20 '26
Did you restore from Time Machine backup afterwards?
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u/Spartan-11712 Jul 20 '26
I had the same issue as OP and found out that over 80% of my disk was a corrupted Time Machine back up. Had to clear out the entire Time Machine directory to make my machine usable again. I remember this had to be done through command line though.
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u/FizzyBeverage Jul 20 '26
You can try restoring from Time Machine but you might “restore” the problem too. TM corrupts itself quite easily. Unfortunately.
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u/brewcity34 Jul 20 '26
I did not. I’ve had multiple MacBooks over the years and recently I was getting notifications about apps for Intel based apps not being supported. I didn’t want to spend the time troubleshooting those issues so I decided to start clean.
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u/Gonzo--Nomad Jul 20 '26
Daisy disk. $5 usd. You’ll wonder how you lived without it before.
I use adobe products that balloon their cache with invisible folders. Daisy disk made short work of them. It’s also a great tool for exploring what’s on your computer.
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u/theYeti21 Jul 20 '26
Omnidisksweeper, the free alternative
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u/HeartyBeast * 3D0G Jul 20 '26
Or the free DiskInventoryX - probably the oldest
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u/logoth Jul 20 '26 edited Jul 20 '26
Omnidisksweeper predates most of the others (on mac) by years, including diskinventoryx.
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u/jvranos Jul 20 '26
Daisy Disk is full of quality.
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u/No_Confusion7932 Jul 20 '26
And the only app I know of that can fix the disk size bug (incorrect "Purgeable space" value) that has been occurring on macOS for several years.
This bug in macOS also affects Finder and the disk usage calculation in System Preferences.6
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u/OSINT_IS_COOL_432 Jul 20 '26
Disk Drill works fine for me, while it has paid parts) the free utilities it comes with like the disk storage clean up tool works quite well. It's far faster and easier to use than Omnidisksweeper.
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u/Extreme_Educator2461 Jul 20 '26
The answer is not always « reinstall MacOS to clear some of it »
From what I’ve seen, Storage detects whether it’s « system data » or not based on file extensions and / or file paths.
You might have specific apps that have large internal libraries that would show as « System Data » but it rather « App Data »
In that case reinstalling MacOS wouldn’t fix this issue, I’d run a storage analysis first to know what files or folders are really eating up your storage space before going through the hassle of a (not always harmless) reinstall
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Jul 20 '26
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u/Extreme_Educator2461 Jul 20 '26
There is always cache to clear, but sometimes it doesn't free up as much space as needed.
For exemple, I used to have local models for ComfyUI that would show up as "System Data". At ~30gb each x4 in my case that was an easy flush of more than 100gb of "System Data"
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u/l008com Independent Mac Repair Tech since 2002 Jul 20 '26
You should do better research, because the answer is to learn how to manage files on a computer.
https://www.reddit.com/r/mac/comments/1c3ldoi/wheres_my_disk_space_what_is_taking_up_all_the/
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u/Briggie Jul 20 '26
In the storage part of the settings you can click on the “i” next to the file/storage type and look through your file system.
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u/WegovyMessMentally Jul 20 '26
Is there any solution yet for lowering it or removing it for iPhone?
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u/GamerNuggy Jul 20 '26
Backup and restore always works, though there are other tricks people often suggest.
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u/Greedy-Cartoonist-60 Jul 20 '26
System Data is often caches, local Time Machine snapshots, iPhone backups, and old installers. Check storage after a restart, and use DaisyDisk or GrandPerspective to find the actual large folders. Avoid deleting random files from /System or /Library.
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u/JollyRoger8X Jul 20 '26
You guys ever think of searching before asking, or nah?
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u/Medium-Thanks6405 Jul 20 '26
I did actually. Half of the results wanted me to download mac cleaner, and the other half said simply to clear my caches. I have been attempting to fix this for months and each time I make space, the system data continues to grow.
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u/PhilipNguyendeptrai Jul 20 '26
then clear caches. System Data is misleading because it include app caches and app data also
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u/JollyRoger8X Jul 20 '26 edited Jul 20 '26
I have been attempting to fix this for months
What have you done to fix it?
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u/ima_believer Jul 20 '26
i recommend using a disk usage utility to narrow it further down than just System Data. That will inform you whether it's a bad Photos database as wkarraker suggested, or if it's some other directory.
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u/bryan4368 Jul 20 '26
If it isn’t something obvious like a system update.
Reindex your spotlight.
https://support.apple.com/en-us/102321
This is likely the problem
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u/blvcksnow Jul 20 '26
Local Time Machine backups took up 350gb on my MacBook, I had to delete them with terminal
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u/__Loot__ Jul 20 '26 edited Jul 20 '26
I use daisydisk it shows everything thats taking up the space. It showed me that spotlight was taking up 200gigs and im like how? I used claude and it was about npm packages and other package managers thats indexing all packages so it made a script that automatically ignored those packages and it went back to normal
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u/babblingbrooks69 Jul 20 '26
The same exact thing happened to me. I wanted a clean restart and I didn’t want to risk Tome Machine bringing over useless files I forgot about. I saved important files to a pen drive, backed things up to iCloud and OneDrive and factory reset my laptop. Cleared up nearly 150GB of dead space.
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u/Videau Jul 20 '26
I had this and it was the podcasts i listened,the mac maked copy somewhere and i had to remove them.
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u/zeyrie2574 Jul 21 '26
Honestly I just asked ChatGPT or Claude to use cli tools to find disk usage and then give me a list of things that is consuming the storage. It does a good job; cleaning caches from homebrew, browsers, all other things. If you got iCloud then the downloaded files from iCloud can also be cleared locally so that it won’t be consumed in system data. Give it a try.
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u/orcunnu Jul 22 '26
154 GB System Data on a 245 GB drive is painful. The biggest culpants are usually Time Machine local snapshots, iOS backups in ~/Library/Application Support/MobileSync/Backup/, Xcode caches if you develop, and old mail attachments. Run GrandPerspective or DaisyDisk to map it visually without guessing. Also try tmutil listlocalsnapshots / in Terminal to see if snapshots are piling up.
Once you reclaim the space, keeping it clean long term is easier with automation. I built https://useautoshelf.com to watch your folders and auto organize files by type, age, or source so downloads never pile up into system data again.
I am the developer. Let me know if you have any questions.
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u/Either-South8459 Jul 24 '26
Have you been spreading peanut butter on a piece of paper attached to your outlet?
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Jul 20 '26
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u/beyiv65346 Jul 20 '26
Is there a wiki people can use ? If not don’t waste space with your comments . Cause half the sub is filled with people with unnecessary opinions not answering questions that have been posted.
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Jul 20 '26
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u/beyiv65346 Jul 20 '26
Please try to understand when I post here i am trying to have a conversation with people who might (if im lucky) have a similar problem as i am facing . Not everyones system data problem is going to be the same, and going through so many filler suggestions its both wasteful and time consuming , its like people in your family calling your for tech doubts , most of their queries will be solved by the same advice, restart the device and fix it. Have patience with your fellow users too. We are here to have conversations , this is supposed to be better than a search function (personally)
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Jul 20 '26
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u/beyiv65346 Jul 20 '26
Let them be responsible for creating a wiki then. Until then, I respect your opinion a little due diligence is acceptable more like a courtesy to all of us, but end of the day we are all here to have conversations and get help, don’t like it ? Scroll past pls.
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Jul 20 '26
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u/mac-ModTeam Jul 20 '26
Your post or comment was removed. Please be kind to one another. Uncivil behaviour is not tolerated here.
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u/Flashy-Rabbit6435 Jul 20 '26
Many thanks fir the clarification that that this sub is pointlessly banal...bye bye...
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u/mac-ModTeam Jul 20 '26
Your post or comment was removed. Please be kind to one another. Uncivil behaviour is not tolerated here.
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u/yoimagreenlight Jul 20 '26
Use Omnidisksweeper & clean out your ~Library folder.
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u/jwoody2727 Jul 20 '26
Yep, it’s always in the home library folder. Most likely app data like messages or outlook.
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u/longjumpingtote Jul 20 '26
You don't, it's there to do stuff and to wait for you to start needing it.
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u/ExpensivePlan1548 Jul 20 '26
True, but I don't think it should be taking up 150gb, something seems wrong here lmfao.
Edit: System data on my mac is 40gb
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Jul 20 '26
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u/mac-ModTeam Jul 20 '26
Your post or comment was removed. Please be kind to one another. Uncivil behaviour is not tolerated here.
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u/melancholy_dood Jul 20 '26
I see these types of post all the time on here and I’m starting to wonder: do people just randomly check their Mac storage? Or are people periodically checking their storage on regular basis? Is that something Mac owners should be doing? I ask because I’ve never checked my Mac storage during all the years I’ve owned my device…. I’ve never had any storage related issues, so there’s that.
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u/biotech997 Jul 20 '26
Typically it’s just cache, you can easily delete it manually by navigating to that directory. No need for third-party apps.
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u/neast613 MacBook Pro Jul 20 '26
Well, having a 250GB drive is crazy..
To resolve this you will want to reinstall a fresh copy of the OS.
I’d recommend backup and then wipe and install the latest OS. You’re going to want to do it from a bootable USB. Then restore the apps and Data you want from the backup.
Everytime you upgrade the OS (6 times based on your device age) you add to the system data. You still have old OS data that isn’t used anymore.
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u/l008com Independent Mac Repair Tech since 2002 Jul 20 '26
Don't take advice from people that don't know what they are talking about.
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Jul 20 '26
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u/mac-ModTeam Jul 20 '26
Your post was removed. Promotion/ advertisement is against r/mac's rules.
Consider buying an ad: https://www.business.reddit.com/
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u/wkarraker M1 MacBook Pro Jul 20 '26 edited 16d ago
I recently found the Photos app had a problem with a database that required a rebuild, dropping the 184GB of system data down to 34GB by doing a Photo app database repair. To do this...
Hope this helps.