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Why does System Data keep increasing?
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I assume you are looking at this from System Information? How much is it and how much has it grown by (plus/minus)?
If we're talking 10-100s GB then you're not the only one:
discussions.apple.com
If you're talking about a few GB it could be normal. I believe System Data includes everything not System and not user Documents/Movies/etc. Then I believe this still holds for Sonoma:
eclecticlight.co
Besides non-Apple applications, this includes the VM volume. So if you're talking about a few GB then it could be that that volume has grown due to swapfiles and sleep images. Sometimes Safari grows so much that it starts spilling things over to VM even though it would seem like you're not doing anything intense.
However, if your situation more resembles one like those other people it's likely a Sonoma-specific system issue requiring one of the approaches they outline (e.g. some people reported solution from upgrading to the latest version of Sonoma).
If we're talking 10-100s GB then you're not the only one:
System Data is taking all drive space in … - Apple Community
If you're talking about a few GB it could be normal. I believe System Data includes everything not System and not user Documents/Movies/etc. Then I believe this still holds for Sonoma:
Ventura volume layout
Updated charts of containers and volumes on boot volume groups for Ventura, with details of cryptexes and what they do.
eclecticlight.co
Besides non-Apple applications, this includes the VM volume. So if you're talking about a few GB then it could be that that volume has grown due to swapfiles and sleep images. Sometimes Safari grows so much that it starts spilling things over to VM even though it would seem like you're not doing anything intense.
However, if your situation more resembles one like those other people it's likely a Sonoma-specific system issue requiring one of the approaches they outline (e.g. some people reported solution from upgrading to the latest version of Sonoma).
I have a brand new iMac M3 and set up new and clean. No migration from any older system. I've only installed a few 3rd party apps from the App Store and one from Topazlabs recently. Before I would never turn off the iMac and recently I've started to let it sleep to see how it runs that way. My System data started around 20gb about a week ago last I checked. This morning after seeing this post and checking mine, it is now 165GB LOL... Which is insane crazy to me.
Update: I turned off the iMac and waited for the external drives to spin down and turn off. Turned it back on and System Data is now 13GB. Problem solved for me. Probably wasn't even a problem, it might have just shrank itself on its own.
This week I'll have it never turn off and see what happens to the system data.
Update: I turned off the iMac and waited for the external drives to spin down and turn off. Turned it back on and System Data is now 13GB. Problem solved for me. Probably wasn't even a problem, it might have just shrank itself on its own.
This week I'll have it never turn off and see what happens to the system data.
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I don't know what the size is of your System Data, I don't know the increase over time.
Obviously it helps what Apple themselves say about System Data. No reason to speculate. If you haven't found it already:
Open System Settings.../General/Storage
The last storage item on that page/dialog is System Data. Apart from showing its size, there's nothing else it tells you. But at the bottom of the page/dialog is the ?-button. Click it.
It ought to bring up the macOS User Guide, chapter 'Change Storage settings on Mac'. You'll see a table with options and descriptions.
At the bottom (again) is 'Other Users, macOS, and System Data'. Here you find what Apple says about System Data.
Indeed, the log files, caches and possible VM files do grow. What isn't mentioned by name, are the db files all over the place. They can grow as well.
System caches tend be cleared after a reboot, log files may start to rotate at a certain size and/or get compressed and a new version is created.
But bugs do exist.
Wallpapers are cached and not cleared by changing a wallpaper or rebooting. Some people who rotate their wallpapers have noticed (literaly) huge increase of memory usage.
Some of the db files might have grown because of a bug, but the bug is (supposedly) fixed. Still the db file is not cleared from the debris.
Etc. etc.
If things get out of hand, there might be ways to (temporarely) reverse the situation (a bit). Regarding Safari, you could look at what bogdanw proposed in another thread.
According to the macOS information on screen, system data concern data the system manages for you.
As I found, there's a lot under your own login directory, caused by all kinds of applications,
wanted or not. A bad example is unwanted stock info which can litter your disk.
To get an idea of the space wasted under your account, start Terminal; it will sit on your login directory.
Then practice this command: du -d 0 -m * 2>/dev/null
Explanation: disk-usage, not in-depth, in Mb, all, error messages suppressed.
Several directories are inaccessible, so the output is not complete: the waste is probably still worse.
;JOOP!
On Thursday evening my System Data was around 10.5 GB. I put my MacBook to sleep and woke it back up on Saturday morning. On Saturday morning, the System Data was 8.9 GB. Started using my MacBook as I usually would (Safari, etc.) and now System Data is 10.1 GB (Saturday evening).
I've noticed one thing though. System Data decreases after opening Safari and the deduction from System Data gets added to the Applications' size (specifically Safari's).
Safari closed:
Safari open:
I've noticed one thing though. System Data decreases after opening Safari and the deduction from System Data gets added to the Applications' size (specifically Safari's).
Safari closed:
Safari open:
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If you measured like I advised, could you see the same difference in the size of files under 'library'?
;JOOP!
Your system data is fine and average. It fluctuates up to 15 or a little more. When you hit 165GB like mine did, and it never goes back down and keeps going higher then there is a problem. Yours look fine.
For comparison, right now my Mac reports 101GB. And I expect it to fluctuate considerably. Doesn't bother me, as I know there is all sorts of stuff counted in that - including logs, caches, databases, libraries, command line apps, backup snapshots, swapfiles, hidden volumes, etc.
In the view you show, macOS has tried to categorise folders and files and everything left over is counted as System Data.
If you want a file system centric view, use a third party app like DaisyDisk or OmniDiskSweeper. Using one of them will lead to many more questions about the parts of macOS that Apple is happy for you not to understand!
Don't worry about your small System Data, but do continue exploring macOS.
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There have been many posts about this issue. The bottom line is that in most cases it is out of your control. You can delete TM snapshots or other things but eventually they usually return. I purposely overbought on storage so that I don't have to worry about it. Right now my System storage is 1.03 TB. It just increased by ~300 GB in the time that I was writing this. Think this is due to TM running. Now it has dropped back to ~700 GB.
We're talking about "System Data" that fluctuates up and down as the OS does its thing. Are you saying that your "System Data" is about 300GB? Just the "System Data" not anything else. My system data right now is 18GB.
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No. When I starting writing this post it was 1.03 TB. By the time I took the screen shot it had dropped again by ~300 GB.
In that case, look at the size of Time Machine snapshots on your boot disk. In DU, Menus> View > Show all devices. Select Macintosh HD - Data, Menus > View > Show APFS snapshots and select both Private Size and Cumulative Size columns. If the snapshots are large you need to investigate - maybe you have some large frequently changing files which should be excluded from TM and backed up in some other way.
Ok so now I'm going to run the iMac with Default Sleep. 10 min screen goes blank and iMac goes to sleep. When I did the near 1 week test of never sleep, always stay on with the iMac M3 the System Data went from 13GB to 18GB. Now I want to see what happens in a week with the iMac constantly sleeping waking sleeping waking behavior. I started this yesterday and System Data is 24GB as of now.
Thanks. Was unaware of those options.
In Disk Utility there are 23 snapshots right now on my boot disk which comes to a total of 184 GB (8*23). Two of these blew up to >300 GB each temporarily I guess when TM backups were in progress.
DaisyDisk shows 425 GB in snapshots and 381 in hidden space that it can't analyze. That matches the general total of >~700 GB.
They will, if TM is working correctly, disappear after 24 hours. Or if the disk gets full.
Looks like you need to look carefully at what is on your disk. Basically do you have any large files which are changing frequently (or all the time)? Even those you may have excluded from TM backup. The most common example is virtual machines.
If you find your source of large frequent changes, the solution is to move them to a separate volume on your disk and exclude that whole volume from TM backups. You may need to manually delete snapshots to give you the disk space needed to rearrange things.
Don't worry about it.
I'm not worried about it. This is a discussion board. I was discussing.
I'm not quite understanding the purpose of TM snapshots when I do already backup on a regular basis with DAS drives. My Snapshots on the MBP are around 30GB, 500 GB home folder size and 2TB total storage.
Assuming you are just copying from one disk to the DAS you overwrite the contents of that drive with those of the source drive. There is no backup history. Snapshots allow you to replace a file from an earlier time which was replaced by a later backup.