System Data Overflow Bug - storage full with 170GB of undeletable data!

[Rydawg96]

I have a major issue with my iPhone, and I have found no way possible to fix it! All of the sudden, my storage keeps going full, and there is no way to get any free data whatsoever because of what’s actually consuming it. Of all the 256GB of data on my 16 Pro Max, 170 GB of it is being consumed by system data, aka data that is only supposed to be temporary, not permanent. And the worst part is, nothing I do to free up storage lasts before it consumes it up again. I delete an app that’s consuming a few GB of data, the system data fills it up again. I deleted my Safari cache, did nothing. I even did the date trick, did nothing. And there is no way to clear the cache with a simple button, which there should be. How am I supposed to clear this? Is there any tool available for the Mac that can clear the system data cache without me completely wiping the phone and restoring? Because I already did that a month ago and I don’t want to do it again. There should be an easy fix for this… like my iCloud backup is only 12 Gb for this phone, there is no way that I should have a cache as humongous as 170gb that’s bigger than my permanent data.

 

[Basic75]

Perhaps it's time to try a factory reset. And have you got any weird apps installed, anything that claims to optimize the system (if this crap even exists for iDevices)?

 

[harkon]

I am experiencing the same problem. My systemdata keeps growing without reason. I did a fresh restore of my iPhone last Monday and today systemdata is at 104GB. That’s way to much and a big chunk of my 512 GB capacity. Yesterday I phoned with Apple support but they didn’t com up with a solution jet. I have another phone call scheduled on Thursday and I hope that they have something. I restored a few times already the last weeks and the systemdata keeps growing after few days.

 

[Basic75]

Have you tried using Terminal.app and the du command to track down where all that data is?

Sorry, wrong kind of device.

 

[harkon]

I really wish there was a way to diagnose this. Sometimes the closed iOS system is suboptimal.

 

[Rydawg96]

I am experiencing the same problem. My systemdata keeps growing without reason. I did a fresh restore of my iPhone last Monday and today systemdata is at 104GB. That’s way to much and a big chunk of my 512 GB capacity. Yesterday I phoned with Apple support but they didn’t com up with a solution jet. I have another phone call scheduled on Thursday and I hope that they have something. I restored a few times already the last weeks and the systemdata keeps growing after few days.

Just wondering, which iOS version did you start having this problem? And what iPhone are you using? Mine started with iOS 26 on my 16 Pro Max, never had a problem with this with iOS 18 on the same phone nor on my previous iPhone, the 12 Pro Max, unless I am missing something.

 

[cynics]

Are you getting low storage warning and unable to use the device normally?

iPhone will use storage you aren't using. It's inefficient to spend the resources to make storage available that isn't going to be used for anything. If you aren't using the space there isn't a reason to remove cached data because if you reuse that data again iOS won't need to use battery and data redownloading it.

"System Data includes coaches, logs, and other resources currently in use by the system. This value will fluctuate according to system needs."

 

[Rydawg96]

Are you getting low storage warning and unable to use the device normally?

iPhone will use storage you aren't using. It's inefficient to spend the resources to make storage available that isn't going to be used for anything. If you aren't using the space there isn't a reason to remove cached data because if you reuse that data again iOS won't need to use battery and data redownloading it.

"System Data includes coaches, logs, and other resources currently in use by the system. This value will fluctuate according to system needs."

Well it did cause it a few times. And besides, there’s no reason why it should be this large, especially if it’s only supposed to be temporary. This data should have been reduced after a few days, and if it’s really only temporary, it should automatically shrink when I get the low storage warning, which it is not.

 

[dcmaccam]

Well it did cause it a few times. And besides, there’s no reason why it should be this large, especially if it’s only supposed to be temporary. This data should have been reduced after a few days, and if it’s really only temporary, it should automatically shrink when I get the low storage warning, which it is not.

I just checked my iPhone 16 Pro 128 GB my system data is only 1.41 GB and I have seen it less than 1 GB. Now I don’t use iCloud at all so maybe iCloud has something to do with it!

 

[ifxf]

Do you have Apple AI enabled?

 

[Rydawg96]

Do you have Apple AI enabled?

I did but turned it off. Did not help reduce the system data.

 

[adrianlondon]

I did but turned it off. Did not help reduce the system data.

I read somewhere that if you turn AI off, it will only delete the associated system data if the device starts to run out of space. This was for MacOS, but I'm assuming iOS is similar.

 

[Rydawg96]

I read somewhere that if you turn AI off, it will only delete the associated system data if the device starts to run out of space. This was for MacOS, but I'm assuming iOS is similar.

Well my device is close to running out of storage and it might hit that tonight, so hopefully if it does the system data shrinks. If not, I’ll have to do another system restore (unless iOS 26.2 comes out tomorrow and the update fixes the bug).

 

[xodbox]

Same issue made me post here. It’s frustrating.

 

[Thor_9]

Well my device is close to running out of storage and it might hit that tonight, so hopefully if it does the system data shrinks. If not, I’ll have to do another system restore (unless iOS 26.2 comes out tomorrow and the update fixes the bug).

Force the device to reduce storage. What happens if you try to download a large app.

 

[cynics]

Well it did cause it a few times. And besides, there’s no reason why it should be this large, especially if it’s only supposed to be temporary. This data should have been reduced after a few days, and if it’s really only temporary, it should automatically shrink when I get the low storage warning, which it is not.

Ahh I see the confusion, my bad.

To be more clear, cache data management is handled by the app, not iOS.

iOS will only clear an apps cache if free storage space reaches <10-15% so the phone retains functionality.

System Data isn't just app cache either. Downloads, sync'ing, indexing, file decompression, etc all temporarily reside there. During a sync, backup or large file transfer it will increase system data substantially and should drop once done.

There is a chance iOS 26.2 "fixed it" however if that's the case I would keep an eye on it and pay attention to the apps you're using. If you see it getting really high again you might see what's going on.

When you 'Offload app' it will clear that apps cache, if you are patient enough you can find out if it's a bug with an app/iOS by just offloading apps one at a time. Streaming and social media apps can be storage hogs, so can certain games that have downloads within the app. But even more so is photo, music and video editing applications that use raw formats and/or render during production.