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.

 

[gooutside]

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

Perhaps this is true in theory – but in reality the System Data on my iPhone consistently causes the entire phone to be unresponsive and brick up.

I have done a full restore, I have done every trick you can find in Reddit threads, I have done a sync with the computer – no matter what, every time (and I mean every time) the System Data eventually fills every single piece of available storage.

I have no idea what is causing this and Apple has told me through several escalated support calls that they can't and/or won't do anything about it, either. Their "solution" was for me to reset the phone and not restore from a backup and to create a new iCloud account, which is, pretty obviously, not a realistic solution.

 

[dferdo04]

I've had the same problem since about mid November on my iPhone 13 Pro. I've also had my phone become completely unresponsive.

The first time I erased it and restored from Mac, and 2 weeks later, I had the same problem but worse (about 170GB System Data). Took it to the Genius Bar, and they told me to erase it and not restore, but I tried a DFU erase and iCloud restore to attempt to save my data. Now, about 3 weeks later it's back up to ~105GB.

So today I've done some digging into the iOS Storage Logs from my phone, and I've compared the ones I gathered on 10 Dec to the ones from today. The one standout thing is that this folder seems to have grown by 61.07GB: /private/var/containers/Shared/SystemGroup/systemgroup.com.apple.lsd.iconscache/Library/Caches/com.apple.IconsCache/
In that same time, my total used space has increased ~68GB.

I realise this doesn't provide anything we can immediately do, as far as I know, but it at least gives a potential cause of the problem.

This was initially on iOS 26.1, and now iOS 26.2. Though my System Data problems started during the iOS 26 beta over the summer, but that may or may not be related.

 

[gooutside]

So today I've done some digging into the iOS Storage Logs from my phone, and I've compared the ones I gathered on 10 Dec to the ones from today. The one standout thing is that this folder seems to have grown by 61.07GB: /private/var/containers/Shared/SystemGroup/systemgroup.com.apple.lsd.iconscache/Library/Caches/com.apple.IconsCache/

I think we’re experiencing the same issue. Your story sounds remarkably familiar.

Please – I desperately want to know how you’re gathering these logs. I have been desperate for any kind of diagnostic information to help me understand what’s going on with this garbage bug. How are you gathering the iOS storage logs? I simply must know!

 

[ghostface147]

Has anyone erased the device and started from scratch? No iCloud backups, just a brand new setup.

 

[gooutside]

Has anyone erased the device and started from scratch? No iCloud backups, just a brand new setup.

No offense, but you do understand how this is not an actual solution, right?

I mean, I have been using an iPhone since 2008, carrying my backups forward, and I’m – like, honestly I can’t believe I have to say this – I’m not going to just start over from scratch like it’s a brand new phone. I mean – that’s basically the equivalent of asking me to switch to Android to solve this problem.

I’m sure you have good intentions but – man, this is just a total non-starter. This is an absolute and total issue that is 100 percent on Apple to resolve and I’m not really in the mood to pretend to resolve it for them by throwing away almost two decades of work on my iPhone.

 

[ghostface147]

No offense, but you do understand how this is not an actual solution, right?

I mean, I have been using an iPhone since 2008, carrying my backups forward, and I’m – like, honestly I can’t believe I have to say this – I’m not going to just start over from scratch like it’s a brand new phone. I mean – that’s basically the equivalent of asking me to switch to Android to solve this problem.

I’m sure you have good intentions but – man, this is just a total non-starter. This is an absolute and total issue that is 100 percent on Apple to resolve and I’m not really in the mood to pretend to resolve it for them by throwing away almost two decades of work on my iPhone.

It’s a solution that resets the clock. There’s no way to get into the file structure and start cleaning out files to see what’s causing the issue. This is something the affects iPhones and it doesn’t seem there is anything they are doing to resolve it. I understand that for some people it’s a non-starter, but what is the best solution now? Nothing. Absolutely nothing.

Personally I wipe and load my iPhone each new model I get. No restores, nothing.

 

[gooutside]

I understand that for some people it’s a non-starter, but what is the best solution now? Nothing. Absolutely nothing.

Correct! There’s nothing I can do, right now, other than give up – and also to bring awareness to this ongoing issue with the hopes that others who are having the same problem will be able to work together to elevate it.

But, of course, there is a large organization – one that actually created the iPhone, itself, as well as the software that runs on it, and they could resolve this since they created the issue.

What I’m most frustrated about is that this is a very well-known issue and Apple is dispensing the same advice that you’re offering: give up and throw away years of your life. That’s a non-starter, and, frankly, it’s not useful advice. If I didn’t care about my backup data or my history, don’t you think I would have done exactly what you suggested months ago?

 

[dferdo04]

Please – I desperately want to know how you’re gathering these logs. I have been desperate for any kind of diagnostic information to help me understand what’s going on with this garbage bug. How are you gathering the iOS storage logs? I simply must know!

I'd just drafted a long reply saying that you needed to have Apple request the information from you in response to a Feedback Assistant bug report, but thanks to another MacRumors thread, I've realised I was using the wrong category of bug report, so you actually can gather these yourself!

To get the logs:

1. Open the Feedback Assistant app. (If you aren't on the beta, type applefeedback:// into Safari's URL bar which should open it).
2. Draft a new bug report. For "Which area are you seeing an issue with?" choose Settings.
3. For "Which area of Settings are you seeing an issue with?" choose iPhone/iPad Storage.
4. A button will appear at the bottom in the attachments section to Gather iOS Storage Logs.

This could take a few minutes, but once it's finished, you can click on them and then choose the only file "FilesystemMeta-...", and then you'll need to share it to a computer via any normal method, otherwise it'll be fairly impossible to analyse them, and you'll need to extract the .tgz file.

They're not easily readable at all, but after some time looking at mine, I found the file that contained the useful information was called private_var-dev_disk1s2.fslisting. I'm assuming that the disk number will be the same for everyone. This contains details of every file and folder on that particular partition, I believe. So it's not really feasible to analyse this manually, particularly since only files display have their size, not folders.

I got Gemini to write a short Python script that would take 2 sets of these files from different times, and calculate which folders and files had grown the most in size. I'd be happy to share this, though of course you'll only have one set of files, so it'd have to be a slightly different.

But first, let me know if you have any trouble getting hold of the logs, and once you've got them I can offer some more advice. I'll be disappointed if it turns out we've got separate problems!
If you do end up submitting a bug report about the System Data problem, feel free to mention my feedback FB21312517 as well to hopefully build a bigger picture.

 

[gooutside]

Hot-diggity-dog! I was able to get the storage logs, and ran a script just to analyze the private_var-dev_disk1s2.fslisting file. It revealed that, yes, I also have an enormous directory: /private/var/containers/Shared/SystemGroup/systemgroup.com.apple.lsd.iconscache . It's 50.2 GB. Deeper inside that directory are 161,000+ files inside, just a few MB each, with names like this: F5C1530A-055E-3CA0-AA9B-E0C05AED3709.isdata.

And that's not all – I found an old diagnostic I ran from November, ran the script and found that it, also, had an out-of-control icon cache.

So – it looks like there's some kind of dumb crap going on with this icon cache. I tint my icons red when in Sleep mode. I might try turning this off, for now.

But – I think we're on to something with this icon cache. Any ideas on what we can do with this?