Taking a backup of your Android device is very important, especially when you tend to play around with your device such as installing a third-party ROM. If you install a custom ROM and something breaks in the installation process; you can lose all your data if you didn’t do a Nandroid backup.
As you probably know, Android doesn’t have a backup system like the users have for iOS, for example. The ADB backup method doesn’t backup data for every application and the new backup system for individual applications from Google is not of much help unless the developersadd the code to that specifical application.
For this reason, many users install a Custom Recovery that can help them make a Nandroid backup to their devices.
Among many features, the Nandroid backup solution is available in most Custom Recovery environments.
The Nandroid backup is a de-facto standard directory configuration for making perfect mirror backup image of an Android device. By making the Nandroid backup, you can save exactlyeverything, from your personal data to all the system files. So, you can save the operating system itself (making a copy of your stock or custom ROM will allow you to return to it if need it), your apps (including those installed by yourself), pictures, music, videos, messages, games and the progress that you made it in them, all wallpapers, all widgets, all login and account settings, all ringtones, all system settings, all stored passwords, including WiFi passwords and so on.
As the TWRP is the most used custom recovery, we will detail the steps to follow in order to make a Nandroid backup for your OnePlus 5 device, once you have installed this custom recovery on your device.