System Data uses 218 GB. How do I delete data from System Data?

Well,

I manage 10 Macs.. some Mac mini's 2012, some newer M1 .. All have suffered in the last month catastrophically increase in this System Data.. filling up HD space.

We tried to use iCloud as our main Cloud file storage and have about 20gb of data there for the company.

Smaller Macs with 128gb hard disks.. normally only 50% full.. now are 97% full and we had to use Omnidiks sweeper to clean out the Cloud Cache (20+GB). Strange enough there is also MAIL Cache.. which we did not delete yet. .The iDisk continued to work.. even though we deleted this darn Cloud Cache..

But.. hey Apple.. ! There is something wrong with this folder.

We use Filemaker.. that too writes some 10+GB Cache files.. which we deleted..

One machine we managed to go from 127gb down to 70gb.. only to find it after 24 hours being full AGAIN..

Ok.. I understand that apple thinks this is all legacy stuff.. but on my M1 Mac.. I Had only 20gb left.. delete some of these caches by nuking with Omnisweaper .. now I have 90gb.. next day I look.. I have 70gb.. next day again 90gb.. Time Machine uses this space too.. Anyway.. this is not good.. Something is off..

We will probably abandon iCloud as Team repository.. until somebody posts a real solution and these machines with macOS start behaving "rationally" again.

Yes, this is ridiculous. My M2 Air went from 50% storage to 97% within 24 hours. Suddenly, my iCloud is full and my hard drive is full. This is bs. System Data is a bit ominous. Their solution is not a solution.

rwsell Said:

"System Data uses 218 GB. How do I delete data from System Data?: I can not update macOS because memory is full"

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Tips on Freeing Up Internal Mac Storage:

Clear Space:

Try clearing internal storage. Do so, though use of the following:

I. Moving Photos:

Export your Photos to an External Location: Move your Photos Library to Save Space on your Mac - Apple Support

II. What Space to Clear:

A. Clear Temporary Internet Files:

Clear your Temporary Internet Files(Cookies & Cache) of Safari:

• Cookies perform remembrance of certain site-entered data.
• Cache keeps a snapshot of the last time you visited a site.

Go Here: Manage Cookies and Website Data in Safari on Mac - Apple Support

Also...



B. Clean TV and Music Libraries:

Remove all unneeded files from your TV and Music Libraries. Full-Movies take up 2-4GB typically, and a bunch of those would take up a load of storage, ideally. So, if you have any movies that are not needed, then delete them.

Also...



C.See this Link:

• Optimize Storage Space on your Mac - Apple Support

rwsell Said:

"System Data uses 218 GB. How do I delete data from System Data?: I can not update macOS because memory is full"

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Clearing System Data on a Mac:

Overview what is mentioned here: I am trying to upgrade but it says I don't have enough space for it - Apple Community

Part 1 of 2

Not possible

The final word from Apple on Managing the " Other/ System Data “ Category

Other / System Data: Contains files that don’t fall into the categories listed here. This category primarily includes files and data used by the system, such as log files, caches, VM files, and other runtime system resources. Also included are temporary files, fonts, app support files, and plug-ins. You can't manage the contents of this category. The contents are managed by macOS, and the category varies in size depending on the current state of your Mac.

Part 2 of 2

The best i can suggest is below

It is generally a good computer practice to alway keep at least 15% to 20% of the Total Drive Capacity’s as Empty Space. Allowing the computer to drop below these guidelines may eventually, cause unintended consequences.

There is Purgeable Space and there is Empty Space.

Purgeable Space which is Controlled by the Operating System. When the Operating Systems decides the computer needs additional Empty Space, it will move a portion of the Purgeable to Empty space

AFAIK - there is no User Actions to hasten this transition from Purgeable to Empty Space

It can day or longer before this will occur  

The links below will assist in identifying what is taking up space on the Internal Drive and provide possible ways to remove data that is under the direct control of the User ( Home Folder ) . 

Rebuild the Spotlight index on your Mac

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

Free up storage space on your Mac

OmniDiskSweeper Safe to use

GrandPerspective 

How to delete Time Machine snapshots on your Mac.  

Often caused if the Time Machine Drive has not been attached  to the computer and TM Backup is set to run on a Schedule. 

TM Backup will make Snap Shot on the Internal Drive awaiting the TM Backup Drive to be attached. 

Only then will the Snaps Shots be transferred to the External Drive and deleted the Internal Drive.

See used and available storage space on your Mac

Locate backups of your iPhone, iPad, and iPod touch

Notation - If the user is using a cloning software like Carbon Copy Cloner - and https://bombich.com/kb/ccc6/automated-maintenance-ccc-safetynet-folder suggest tweaking the Safety Net Feature in this software. It may be making additional Snap Shots that are not being Cloned to the Eternal Drive. If this should be the case, these Snap Shot could be using additional space on the drive 

I posted these instructions in another thread, but they apply to you too.

Your hard drive is full. It was full yesterday and it's full today.

Start deleting files. Don't delete any files in any hidden folder. Especially don't touch any "Library" folder. This is primarily a caution against most of those "clean up" tools. They can cause catastrophic damage.

Wait.

It will take a day or two for the files to be completely removed. Don't panic. Your hard drive is already full. It's going to take a few days to get any space back. Until then, the computer will be horribly slow, buggy, and crashing left and right. It shouldn't matter through. Then only thing you should be doing with the computer right now is deleting files. If you want to save them, copy them to an external drive. Don't use your Time Machine backup for this. Keep that unplugged for the time being. Copy any files you want to save to a new external drive. You can try iCloud, but only at a later date when you have things under control. Try to make any major changes other than deleting files will only make your life worse.

Once you have about 150-200 GB in free storage, as listed in Disk Utility (and only in Disk Utility), then you'll be OK to resume using your computer again.

The System Data is what was earlier called Other category and is a potpourri of files which can 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: browser, Mail

• Mail messages & attachments

• Fonts, plugins, extensions

• Safari reading list

• iTunes backups

• Crud resulting from jailbreaking your iDevice

• Game data

• Saved data files

• Call history

• Notes

• Media

• Voice memos

• 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

• Files created and modified by other user accounts on your Mac.

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.  You can use this free app, GrandPerspective, to find the largest files on your drive so you can determine if they can be deleted or moved to an external HD for storage.

Note: you can empty the Downloads folder after the apps and/or updates that were downloaded have been installed or applied.  Some users have found a couple of Gigabytes of files in their Downloads folder which are no longer needed. 

Pierre Froelicher1 wrote:

We tried to use iCloud as our main Cloud file storage and have about 20gb of data there for the company.

Smaller Macs with 128gb hard disks.. normally only 50% full.. now are 97% full and we had to use Omnidiks sweeper to clean out the Cloud Cache (20+GB). Strange enough there is also MAIL Cache.. which we did not delete yet. .The iDisk continued to work.. even though we deleted this darn Cloud Cache..

But.. hey Apple.. ! There is something wrong with this folder.

By enabling iCloud you are now syncing files to those other machines which may be why you are losing even more storage space after enabling iCloud.

120GB (that is space that you actually get with a 128GB SSD) is way to small for most people, because you need at least 20GB - 30GB of Free storage space available at all times...the OS easily takes up 20GB or more...probably closer to 60GB, plus then your third party apps, then your data....you can see there isn't much room for local data). Just because Apple is willing to sell it does not mean it is a good option. I have seen Apple sell way underspec'd Macs for years. I still recall when we received an iMac with just 1GB of RAM....the minimum at the time should have been 2GB or even more...one of our workers didn't correctly spec the new Mac...it barely booted a bare bones version of macOS.

It would be better to start your own question. Although you may be experiencing the same problem, I'm sure the cause and solution are much different than with most people here.