Why are iTunes backups so darned big?

[zorinlynx]

I just did an iTunes backup of my phone and it took forever (about 20 minutes). I found the backup in the MobileSync directory and it's a colossal 33GB.

Meanwhile, my iCloud backup of the same phone is only using 4.2GB.

Does anyone know what could be accounting for the extra 29GB or so? I don't have anything excluded from my iCloud backup, and while I'd expect a difference of a few % between the sizes due to differing storage methods and such, a factor of seven is a bit too much to ignore.

 

[Mlrollin91]

I just did an iTunes backup of my phone and it took forever (about 20 minutes). I found the backup in the MobileSync directory and it's a colossal 33GB.

Meanwhile, my iCloud backup of the same phone is only using 4.2GB.

Does anyone know what could be accounting for the extra 29GB or so? I don't have anything excluded from my iCloud backup, and while I'd expect a difference of a few % between the sizes due to differing storage methods and such, a factor of seven is a bit too much to ignore.

My iCloud backup for my Air 2 is 100MB and my iTunes backup is 900MB. I have dissected the backup with some backup explorer application and found the root of my problem. I sync about 2GB of photos via iTunes. The iTunes backup create a thumbnail for each photo and stores it. Maybe incase you can't resync those photos via iTunes after real tiring your device. Not sure. But the 2GB of photos equaled about 750MB of thumbnails. The other 150MB was just system stuff.

 

[zorinlynx]

Interesting, so it may be backing up my photos, despite the fact that they should be considered purgeable data because they're in iCloud Photo Library and I have optimized storage on? Talk about wasteful. I already have those photos backed up on my Mac, in Time Machine, on my own personal offsite backup system AND in iCloud. I don't need yet ANOTHER backup of my photos, one which isn't complete anyway.

Damnit Apple.

 

[Mlrollin91]

Interesting, so it may be backing up my photos, despite the fact that they should be considered purgeable data because they're in iCloud Photo Library and I have optimized storage on? Talk about wasteful. I already have those photos backed up on my Mac, in Time Machine, on my own personal offsite backup system AND in iCloud. I don't need yet ANOTHER backup of my photos, one which isn't complete anyway.

Damnit Apple.

I don't know if any iOS 10 backup explorers exist. Last time I checked was iOS 9. But iBackupbot may help you to double check.

 

[akash.nu]

Generally the items on iTunes backup are more detailed than iCloud backup. Because it's assumed that you are more likely to restore from iTunes backup when you may not have data connection. In such scenario iCloud backup won't work.

Eg. iCloud backup doesn't actually backup your apps but iTunes backup do.

 

[Mlrollin91]

Generally the items on iTunes backup are more detailed than iCloud backup. Because it's assumed that you are more likely to restore from iTunes backup when you may not have data connection. In such scenario iCloud backup won't work.

Eg. iCloud backup doesn't actually backup your apps but iTunes backup do.

iTunes backup does not back up your apps. Only the app data. Just like iCloud backup.

 

[akash.nu]

iTunes backup does not back up your apps. Only the app data. Just like iCloud backup.

It does backup the apps as well. That's why you get the notification "There are apps on your iPhone which are not in your iTunes library "

 

[KALLT]

It does backup the apps as well. That's why you get the notification "There are apps on your iPhone which are not in your iTunes library "

It has never backed up apps. In the past, iTunes could also transfer purchases (apps, music, etc.) from your iPhone to your library before making the backup. It did that automatically during the syncing process. It does not do that anymore since iOS 9, at least for apps. iTunes does not back up data that either originates from your iTunes library or the iTunes Store. Apps that aren’t located in your library when you restore an iPhone will just not be restored, but the apps’ data will still be transferred, allowing you to download the app from the App Store and using it with the existing data.

 

[Mlrollin91]

It does backup the apps as well. That's why you get the notification "There are apps on your iPhone which are not in your iTunes library "

Because if you don't have the app in your iTunes library, the app cannot be reinstalled on the device after you restore, and the app data that is saved in the backup cannot be restored. Only the app data is backed up, not the app itself. Otherwise my iTunes backup would be 50GB+. Not 900MB.

 

[akash.nu]

Because if you don't have the app in your iTunes library, the app cannot be reinstalled on the device after you restore, and the app data that is saved in the backup cannot be restored. Only the app data is backed up, not the app itself. Otherwise my iTunes backup would be 50GB+. Not 900MB.

That actually could be dependent on other options you've chosen. There's a specific tick to choose if you'd want to backup your apps. It's unticked for me as well. The app as a whole get backed up if that option is ticked and that's why you can install the apps even if you don't have connection to internet when you restore from backup. I've seen the app binary files within system files. They physically get copied. That's how iTunes backup works.

 

[Mlrollin91]

That actually could be dependent on other options you've chosen. There's a specific tick to choose if you'd want to backup your apps. It's unticked for me as well. The app as a whole get backed up if that option is ticked and that's why you can install the apps even if you don't have connection to internet when you restore from backup. I've seen the app binary files within system files. They physically get copied. That's how iTunes backup works.

I have literally no idea what you are talking about. There is no option in iTunes to backup the app to the actually backup, only the data. Please provide proof of your statement, because I've been doing this for 10 years now and what you describe has never been the case. The reason why you can install the app with no internet connection is because the app is physically saved on your computer, in your iTunes library. Has nothing to do with backups.

https://www.quora.com/Does-iTunes-backup-the-entire-iPhone-OS-or-only-the-apps
https://discussions.apple.com/thread/4464810?start=0&tstart=0
https://support.apple.com/en-us/HT204136

Directly from Apple.com

iTunes backups
From your Mac or PC, you can make a backup of your device in iTunes. Syncing your device with your computer isn't the same as making a backup. An iTunes backup includes nearly all of your device's data and settings. An iTunes backup doesn't include:

• Content from the iTunes and App Stores, or PDFs downloaded directly to iBooks (You can back up this content using Transfer Purchases in iTunes.)

 

[akash.nu]

I have literally no idea what you are talking about. There is no option in iTunes to backup the app to the actually backup, only the data. Please provide proof of your statement, because I've been doing this for 10 years now and what you describe has never been the case. The reason why you can install the app with no internet connection is because the app is physically saved on your computer, in your iTunes library. Has nothing to do with backups.

https://www.quora.com/Does-iTunes-backup-the-entire-iPhone-OS-or-only-the-apps
https://discussions.apple.com/thread/4464810?start=0&tstart=0
https://support.apple.com/en-us/HT204136

Directly from Apple.com

iTunes backups
From your Mac or PC, you can make a backup of your device in iTunes. Syncing your device with your computer isn't the same as making a backup. An iTunes backup includes nearly all of your device's data and settings. An iTunes backup doesn't include:

• Content from the iTunes and App Stores, or PDFs downloaded directly to iBooks (You can back up this content using Transfer Purchases in iTunes.)

Yes the apps are stored in the library. I see what you mean. Apologies, yes you're right. It was 3 in the morning. I wasn't thinking straight.

 

[Mlrollin91]

Yes the apps are stored in the library. I see what you mean. Apologies, yes you're right. It was 3 in the morning. I wasn't thinking straight.

No worries, no need to apologize. I was just very confused.