How to backup your android phone using Ubuntu

Android backup 

• If not enabled, enable developer mode by tapping Settings > About phone > Build number (7 times)
• If not enabled, enable USB debugging in Settings > Developer options > USB debugging
• Execute on your computer

  adb backup -apk -shared -all

This should hopefully create backup.ab with all of your apps, OS, and data. Later, after reflashing with Android (or rooting / unlocking) you will be able to use

adb restore backup.ab

to restore all of your data.