Precautions before upgrading iOS9 for iPhone6:
1, important file, please make data backup in advance.
For security reasons, it is strongly recommended to use iTunes or iCloud for complete data backup, so that all your local applications and data stored outside iCloud can be backed up. When restoring, you can choose to restore all applications and data, or delete them as needed.
After updating to iOS9, you can choose to use iCloud or iTunes on the backup page in the initial settings. In addition, iOS9 adds the function of "transmitting data from Android devices", and users can wirelessly transmit the address book, information, photos and videos, browser bookmarks, email accounts and calendars on Android phones to iOS devices by installing the "transmit to iOS" Android application (which will be released together with iOS9). At the same time, the iOS device will automatically download and install the free apps you use on your Android phone, and the paid apps will be added to the "Want to Buy List" in the App Store.
Of course, you can also upgrade to iOS9, set it as a brand-new device to experience, and then back it up from the settings-iCloud-or restore it from iTunes.
2. Can I still receive the official version update push of iOS9 after upgrading to iOS9 GM?
At present, the version number of iOS9 GM is 13A340. Judging from the past practice, it should be exactly the same as the official version of iOS9 pushed by Apple tomorrow. You can verify the official version of ipsw firmware by the version number and MD5 information. Therefore, iOS9GM version will not receive this update reminder. After Apple releases iOS9.0. 1 in the future, users who use iOS9 GM can also directly upgrade OTA through "Settings-General-Software Update".
However, in iOS9. 1 Beta 1, there are many compatibility problems in common applications such as WeChat and Netease Cloud Music, such as the disappearance of WeChat wallet, the inability of some netizens to display WeChat official account articles, the inability to accept push, and the inability to play voice and small videos. I suggest you upgrade cautiously.
3, jailbreak users need to pay special attention.
After upgrading to iOS9, it means bidding farewell to prison break temporarily. Although the great god iH8snow showed the perfect jailbreak video of iOS9, the release of jailbreak tools to the public is still far away, and the verification of iOS8.4 has been closed. Once you choose to upgrade, you can never go back.
It is worth mentioning that Apple has opened a little function in iOS9. After the US version is updated, users can directly choose to bring their own Jiugongge Pinyin Panel without modifying the system file to change the version.
Jailbreak users should download the firmware after the official version of iOS9 is pushed, and make a complete recovery in iTunes. Direct OTA update may encounter many problems such as white apples.
4. Good news for users of16GB version: the space required for iOS9 update will be greatly reduced.
IOS9 greatly reduces the size of the remaining space required for updating. The previous official version of iOS8 required about 4.5GB, while the update of iOS9 only required about 1.3GB, which is definitely a great boon for users of 16GB version.
In addition, iOS9 also supports the slimming function of "App Thinning" application, and can only download the basic application resources needed by the current model, so the application space will be greatly reduced. For example, in iOS9, the space occupied by the big game real racing 3 will be reduced to 1gb after installation, and the system will automatically sort out other data downloaded later.
5. After upgrading to iOS9, the security mechanism of Apple ID account will be upgraded to double authentication.
In addition to the original uppercase and lowercase letters+numbers password, Apple will also enable the dual authentication mechanism on iOS9. Once enabled, you need to enter the verification code sent by Apple whenever you use a new device or log in from a web page. The verification code will be displayed on the certified Apple device or in a short message, and you can log in only after entering the verification code.
At the same time, the original screen lock password will be upgraded from 4 digits to 6 digits, allowing users to change back to 4 digits in the password option.
6. Which devices can be upgraded to the official version of iOS9 system?
Finally, please fully charge the device in advance and upgrade iTunes with the original or Apple-certified data cable.
References:
/FAQ/20 1506/20 1506 19 1 10 146 . shtml