For most users, every time the system is very troublesome big upgrade one thing, back up your data - to upgrade the system - restore data, a toss half a day, how to keep the original data in the time to upgrade the phone system becomes everyone one problem is most concerned about, and today we'll introduce how to make your device the next upgrade iOS 9 when the data is not lost, save you the trouble of backup and restore.
(Recover iPad Air/iPad Mini Contacts/Photos/Messages after iOS 9 Upgrade)
Before you begin, I recommend you use the phone when the future develop the habit of regular backups for important information such as photos, contacts and other information is often backed up, so the phone in case the point of the problem, it will not lose important information.
No jailbreak users can update via the following two ways to upgrade to iOS 9 system approach, jailbreak will be upgraded if the user fails recommend jailbreak user selects the "recovery" approach to upgrade, "recovery" mode upgrade will erase the phone's data needs advance backup.(Recover iPhone data after iOS 9 jailbreak)
In the iPhone are supported OTA upgrade, that is, by upgrading the phone without using data lines and computer, the specific step is to [Settings] - [General] - [System update], this advantage is easy to upgrade, do not need a computer data cable, the phone just a few clicks to complete the upgrade, download the system when the upgrade package can continue to use the phone normally.
OTA upgrade also has shortcomings, and that is there space for mobile phone capacity requirements, because the phone will need to download the upgrade package to the storage space before you can upgrade different devices ranging from the need for additional 1GB- 1.9GB, and then have to calculate the the space occupied by the system, generally choose OTA Upgrade, will require sufficient free memory space in the phone. After Apple's continuous optimization, although the space required to upgrade now than before has decreased, but for 16GB of users, each upgrade are quite painful.
Advantages: simple without a computer, upgrade the security, all the information content are not clear
Cons: jailbreak users can not upgrade by OTA way, for storage space requirements.
Another upgrade does not delete the information is to connect iTunes, such is not the latest version of iTunes prompted the first upgrade after the latest version of iTunes, click on the top right corner of the "iPhone" enter detailed preview screen. If you do not separate download firmware, then you simply click the "Update" button, the computer will download the firmware first, then update them to the phone via iTunes.(Recover lost data from iPhone after iOS 9 upgrade)
If you already have firmware, it will omit the download process, saving a lot of time. Firmware, then and then only need to hold down the shift key on the keyboard (mac system users hold down the option key click the mouse), and the "Update" button mouse click on iTunes, click to select the firmware has been downloaded iOS 9, you can We were upgraded.
Jailbreak users need to select "recovery" approach to upgrade, the methodology is here to pay attention to select "recovery" instead of "update", after the jailbreak user Click here to upgrade will clear all data, such as the choice of this upgrade must be done in advance Good data backup !!!
Pros: do not take up extra space on your phone, suitable for small-capacity mobile phone upgrade. Jailbreak iPhone must be used in this way.
Disadvantages: Download the complete firmware upgrade.
No jailbreak users wait for the upgrade is complete, about 10 minutes. At this time successfully upgraded to iOS 9, and what data will be lost all genuine applications can continue to use. If your phone does not escape, but is installed by PC helper application, then after the upgrade is not available, and that needs attention.