Feel free to ignore this article if you did not root Samsung Galaxy Note 2. Because you can’t backup and restore Samsung Galaxy Note 2 EFS without root access. And you don’t need to worry about EFS at all when not rooted.
What is EFS? It is a place that stores your Android smartphone important data like Wi-Fi, Bluetooth MAC address and IMEI (nv_data.bin). Do take note if you are a frequent ROM / firmware flasher or rooted your Android phone. Install unstable or poorly cooked ROM might cause EFS partition to be corrupted or missing. This will make your Samsung Galaxy Note 2 fail to make voice call due to missing IMEI number. Therefore better to make a backup of your Samsung Galaxy Note 2 EFS partition.
There is not much backup / restore EFS tool for Samsung Galaxy Note 2 yet. No Android application to backup / restore EFS on the phone directly. However, there is a tool for Windows, Linux and Mac OS. Basically, you need to enable USB debugging mode first. Then use the tool to backup Samsung Galaxy Note 2 EFS. By the way, better to keep another EFS backup copy on your cloud storage. That’s it. Finally, restore EFS when needed…
Download EFS backup / restore tool for Samsung Galaxy Note 2 here.