App storage on iPhone 12 very large

My iPhone 12 is showing almost out of storage. When I check my usage in settings it shows that the Arc App has 28gb of documents and data stored on my iPhone. My iCloud backup account only shows about 2gb of backups. Is there any way of reducing this amount of storage? I have been using Arc for several years, and don’t want to loose the data, but it would be nice to move some of it off the phone, if at all possible. Thanks!

Hi @harbisonrepair!

28 GB is insane! Yes Arc does use a lot of space, because it records detailed data 24/7, but typical storage space use for a user with 4+ years of data is around 4 GB. So what you’re seeing is 7 times more than expected!

I don’t know why that would be. This is the first time I’ve heard of it happening, and there’s nothing that Arc stores that could possibly come anywhere close to using that much space.

My suggestion would be to delete the app then reinstall and restore from Arc’s backups. Though before doing that, make sure you’ve got an up to date backup in iCloud Drive. You can check when the last backup completed by looking in Arc’s Settings tab → Backup, Import & Export, then under the “iCloud Drive backups” section it will say there.

Though I also recommend doing a full fresh backup first too, to clear out any potential cruft in the backups, which will help the restore to go faster and smoother. To do this, turn off the “iCloud Drive backups” toggle, wait a minute, then turn it back on. (The toggle has a grace period it waits before actually turning off the backups, to cope gracefully with people who might flick it on and off, changing their mind).

When you turn backups off, you’ll see you existing backups renamed to “Previous Backups” on iCloud Drive. Then when you turn backups back on, you’ll see a new Backups folder created.

You can speed up completion of the new full backup by leaving the phone plugged in to power and Arc open in the foreground, with screen lock turned off. That will allow Arc to churn through the full backup as quickly as possible, while Arc is in the foreground. Doing it that way you should be able to get a full backup completed within a day.

Hey Matt, thanks for the reply. I will try your suggestions to resolve the issue. I’m wondering if it has anything to do with iOS 16.2 update, since this just showed up after that. I have been using Arc since April 24, 2014, and I do travel around town a lot, being a remodeling contractor so there are a ton of timeline points. I’m attaching some screen shots just for info. Thanks,

I guess it’s possible that you could have 7 times as much data as the average user with that many years of recording. But I think it’s highly unlikely. It suggests to me that something has gone wrong. Though I’ve got no idea what.

I very much doubt it’s the actual Arc database that’s got that big. I imagine it’ll be something like temporary files that iOS hasn’t automatically purged. Though if that’s what’s happening, there’s no way to trigger iOS to do a cleanup of temp files, so it still leaves us without a way to fix it other than a delete, reinstall, restore.

To explain why I think it’s unlikely to be the database / recorded timeline data: Arc automatically adjusts its sampling frequency depending on current activity type. So for example if you’re walking or running or cycling, it’ll record samples every 2 seconds, but if you’re driving in a car it’ll record samples every 6 seconds. And while inside a visit it’ll only keep one sample for every 2 minutes.

So workout activities (walking, running, etc) result in 3 times as much recorded data as car, train, etc. Which means that if someone had a very large database I’d expect them to be someone who does long outdoor workouts - a long distance cyclist, for example.

Though I guess because all recording outside of visits has a sampling frequency at least 20 times higher than inside visits, someone who spends more time moving between places rather than at places is also going to have more data on average. And given that ratio is higher, that effect is going to be more prominent.

Even so… 28 GB seems outside the bounds of all reasonable expectations. I’m still thinking the most likely cause is temporary files not getting purged by iOS. For which there’s no known workaround (or at at least known to me).

Oh, although… If your backups on iCloud Drive really are 2.9 GB, that could indicate a much bigger database. For comparison, I just checked my Backups folder on iCloud Drive and it’s 500 MB, which would make yours 5.8 times bigger than mine. Though it will depend whether your Arc App folder on iCloud Drive has anything else in it. It’ll be worth checking the size of just the Backups folder (iCloud Drive / Arc App / Backups) to see how big a single full backup is.

Ah, but then there’s the problem of Arc’s Backups folder only ever getting bigger, not smaller, because the backups system never deletes old redundant backup files, so the folder does get crufty over time. Hmm. Probably better to do a size comparison after a full fresh backup.

Heh, just realised after all that rambling I didn’t reiterate clear next steps. I think the best next step will still be to turn off backups then turn them back on, to get a full fresh backup.

You can know when backups have completed turning off by checking to see if the Backups folder on iCloud Drive has been renamed to “Previous Backups”. Once you see that, turn backups back on, and it’ll start on a fresh one.

Regardless of anything else, having a full fresh backup with zero cruft is a good thing to have. And it’ll allow us to do a better size comparison to see whether your Arc database really is insanely large or not. If your database really Is that massive, then delete/reinstall/restore isn’t going to solve the problem, in which case we’ll have to dig deeper into the problem.

Hey Matt,

Thanks for the insight!

Well, I do physically move around a lot on my job sights! I can walk several miles in a day, easy! So, maybe that can explain some of the volume. I checked the size of by latest backup and it shows 37.5 MB. I am attaching some more screen shots just for your reference.

I also downloaded Arc Mini yesterday. It shows 4.59 GB of storage right after instal. Interesting thing is Arc storage went down about the same amount!

When I look at iCloud and check the Arc App folder size it says 2.9 GB, but when I look at the actual folder in iCloud and hit “get Info” it says 59.8 MB (726.8 MB on disk). It’s all very confusing to me! I work with wood!

I’m having some other issues with the iPhone as well, so I might just be doing a complete erase and restore on it anyway…


Yeah, I’m coming round to think it’s possible. Though it’s still an astronomical difference in size, but if when you’re at a job site Arc is picking up lots of short visits with walking between them, instead of a single visit with potentially hours of walking side the visit, then it seems at least possible at a stretch.

Like, if Arc picks up the job site as a single visit, with walking inside it, then it’ll apply its bloat-pruning logic to the samples inside the visit, trimming them down to only 1 for every 2 minutes, but if it’s picking up bunches of short visits at the site, with lots of walking between them, then it’ll be aiming to record all that walking at peak sampling frequency of 1 sample very 2-3 seconds. So the “inside a visit” versus “walking between visits” storage difference is quite significant.

Ah, that’ll just mean it hasn’t finished a full backup yet. It might take a day or two or more to catch up to complete, depending on how much foreground time plugged in to power Arc gets (or how much background time plugged in to power, during which the malevolent iOS gods deem the app worthy of running its scheduled tasks).

Hmm. In that case… that plays into my theory that the problem is actually temp files not getting cleared up. The temp files, if I remember right, are created in a temp folder for the specific app, not stored in the “App Group container” which is shared between Arc App and Arc Mini.

The shared database that both apps access is stored in the App Group container, so for that data you should see it listed as “App Data”, which will then say “Data shared by 2 apps” when you tap into it. But the data that’s only inside each individual app’s container will show separately in the list. So for example for me “App Data” shows 3.8 GB, and then further down the list I see “Arc” with 671 MB. Which means in my case Arc might be carrying around 671 MB of temp files that haven’t been automatically cleared up yet.

Oh wait, just looking at your screenshot, it’s showing “App Group” as “Digital Nomad” (my archaic company name that I haven’t used in over a decade but can’t get Apple to change on the App Store. Sigh).

Okay, so yeah, from your screenshot it really does look like it’s a problem of temp file cruft building up in the Arc app container, while the database itself is still a sensible size (4.59 GB - larger than mine, but not absurdly so).

The Arc App folder on iCloud Drive will also have your “Previous Backups”, which will be the bulk of the 2.9 GB. It might be the new “Backups” folder that’s only around 60 MB so far. Though that does seem a bit ambiguous and confusing. Hopefully it’ll make more sense once the new full backup completes.

If it does turn out to be a problem of temp files not getting automatically cleared out, a fresh start on the phone would presumably fix whatever’s blocking that automatic cleanup process. Though it does seem quite the nuclear option. Something to keep as a last resort.

Actually, I can build in something to Arc to get it to clear the temp files manually. Okay, I’ve put that on the todos for the next release. Fingers crossed that clears it up. Certainly would be less hassle than either a fresh install of Arc or a full reset of the phone!

Hey, the 37.5 MB backup was the old backup, before I toggled it off, so I assume it was a full backup. I also had the automatic daily and monthly exports toggled on as well, not sure if that plays into any of this. I have since toggled them off, just to see. Not sure why I would ever need them anyway!

Wow iCloud says some confusing things sometimes! 32 MB of backups would mean a very incomplete backup, but then it says 690 MB on disk, which is what a full backup should look like.

Does the Settings → Backup, Import & Export view show a last backup completion date now? If so, you’ll now have a clean, full backup, which is a good thing regardless of anything else.

Ah yeah, it’s worth turning those off unless you’re definitely using that data. Those daly exports are just as energy/time expensive as the backups, so they end up competing for the limited background task running time that iOS allows each day.

I’ve almost got the new release ready with the manual cleaning of temporary files. So if that theory is right, the next update should fix it. Hopefully I can submit the update to the App Store today or tomorrow.

Settings - Backup says completed 22 minutes ago, no date.

Wow, you’re quick at getting things done! I look forward to the updates. Hopefully it will solve the mystery!

I’ll keep
Ya posted on my end.

Hope you have a happy holiday!
Thanks :peace_symbol:

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Ok that sounds promising. I don’t doubt what Arc is saying there, but you can double check it anyway by looking inside the Backups/LocomotionSample folder. You should see in there a file for every week of every year that you have data.

And the new build should be live on the store now! It’s on a 7 day phased release, so it probably won’t auto update on your phone immediately, but you can find it on the App Store anyway and can tap the Update button there to get it without waiting for auto update.

The new update deletes all temporary files in the app container that are older than a day. It might take iOS Settings app a little while (no idea how long) to actually notice the change in storage space consumption, but I’m pretty sure this should fix it. And if so, no need to delete and reinstall! Phew.