Mac System Data is large

Hey there!

Yes that’s a bit much for system data, I don’t think I saw any extra partitions using much data either. Any other Users on your Mac?

While in the ~/Library, (That you are familiar with). Can you get the size of Containers? And if you also have a folder called Screen Recordings? There are a few others to check out.

Ive found if Apple Mail is used and Mail logging is enabled, it can continuously generate logs you don’t need.

To check:

Open Apple Mail app.

Click Window > Connection Doctor.

Click “Show Logs”

Click Command i to see the size.

If large delete everything in that folder, empty the Trash, and make sure to disable the option for Mail Logging in Connection Doctor, to prevent this again.

(These logs are deep within ~/Containers/com.apple.mail, so Connection Doctor is an easy way to find them).

I take it otherwise you’ve already also checked in the ~/Library:

Cache

Containers

Group Containers

Logs

Messages

Mail

Screen Recordings

These are my go to’s for Other/System storage, just don’t go delete anything as they may contain important data, however things like Cache and Logs, you can typically get rid of if they get out of line.

Hope that helps!

FWIW. When Time Machine backs up an APFS volume to a backup destination, also formatted in APFS, it creates two snapshots each hour. The first is a "standard" snapshot of the volume which is stored locally, alongside the volume itself, and the second is a synthetic one (that is created on the destination device) that is used to create the backup. The standard snapshots tend to make up the "lion share" of the "system" category. In theory, these snapshots are deleted automatically every 24 hours. Of course, that would only be true if the Mac is running 24x7.

... so deleting these standard snapshots is really not an effective method to reduce the system data. Actually, disabling Time Machine, and then, re-enabling it would do the same thing as the command in Terminal that you used. If you want to stop macOS from creating these TM snapshots all together, you would need to disable TM ... not recommended, unless you have other backup methods that you employ to protect critical data.

Hey again!

I don’t believe taking it into a store will help, as they specialize in hardware repair. Calling Apple Support would be the way to go, even if you need to escalate the case and have them create a ticket if all else fails.

I personally think you may save some time doing all that by backing up, erasing, reinstalling the OS. But would recommend manually moving your data back as opposed to migrating and possibly reintroducing the problem.

Its not as tough at it may seem, main difference would be however setting up your preferences and settings again and re adding your accounts, and possibly reinstalling some apps, although much of that stuff can also be pulled from your Time Machine backup, including data in hidden directories as the ~/Library and other Users, etc. (At least if they’re not being excluded or couldn’t backup due to storage if course).

Its more work, but if you can’t find the culprit, may need to be done.

Hope it works out!

FooFighter1 wrote:

1. This question pops up alot. Can't find anything to help. Left Top Apple Icon -> About This Mac -> Storage. Shows System Data at 325 GB.

I've tried alot of things to reduce the storage on my HD. Gained some disk space back but the System Data has not budge at all. Where's what I've done:

Removed some applications, including Xcode

2. Move my iOS backups to an external drive

3. Cleaned up my Download folder of old *.dmg, *.pkg, *.zip and other larger files.

4. I always keep my ~/Libraries/Application Support, Logs, Caches, clean,

5. Rebooted into Safe Mode. Took a look at Storage, and rebooted in normal node.

6. Delete local versions of timemachine backup via 'tmutil listlocalsnapshotdates and deletelocalsnapshotdates.

7. The free version of Clean MyMac X didn't do much except save me 5 GB.

Have been trying to upgrade xCode for months now, no success. In the meantime the OS has been updated. I aways upgrade to the latest OS on the day it releases or maybe 1 week at the most. I think I sudden realize my 512 GB HD has alot of free space to little. Thought it was videos and music. But I moved those to my external drive.

Any one got any concrete ideas and what can I try?

Thanks.

Lets see the output from your Terminal.app copy and paste:

diskutil list internal

FooFighter1 wrote:

Hi, hello.

Sorry the non-constant width font, or perhaps tabs versus spaces. Any hints would be greatly appreciated.

$ diskutil list internal

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.3 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_APFS Container disk1 500.1 GB disk0s2

/dev/disk1 (synthesized):

#: TYPE NAME SIZE IDENTIFIER

0: APFS Container Scheme - +500.1 GB disk1

Physical Store disk0s2

1: APFS Volume Macintosh HD - Data 427.0 GB disk1s1

2: APFS Volume Preboot 380.2 MB disk1s2

3: APFS Volume Recovery 1.1 GB disk1s3

4: APFS Volume VM 1.1 GB disk1s4

5: APFS Volume Macintosh HD 15.7 GB disk1s5

6: APFS Snapshot com.apple.os.update-... 15.7 GB disk1s5s1

That looks in order...

This is all your user data as you can see.

In this case from the GUI above "Storage. Shows System Data at 325 GB" is in reference to your user data.

In your Terminal output it is represented as " Volume Macintosh HD - Data 427.0 GB"

The macOS takes up a the expected amount: Volume Macintosh HD 15.7 GB

Do some house cleaning; if in doubt:

Try something like OmniDiskSweeper for a GUI to get a good look at itemized file size and location:

OmniDiskSweeper http://www.omnigroup.com/more

User tip: "Other and What Can I Do About It ?"

https://discussions.apple.com/docs/DOC-5142

Empty your Trash — Delete files and folders on Mac - Apple Support

https://support.apple.com/guide/mac-help/delete-files-and-folders-on-mac-mchlp1093/mac

I have never recommended the 'Optimized storage feature"...

How to free up storage space on your Mac - Apple Support 

https://support.apple.com/en-us/HT206996

diskutil seems to have it covered, unless I missed something.

If you run sudo du -shx, etc. etc. for the /Volumes directory(directories), bare any fruit either?

You seem to know your stuff, maybe the disk just needs to be repaired or reformatted, (I know that’s always a last resort, especially depending on the setup you have).

Curious to know how it goes, but good luck, hope you find a solution 🙂!