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.