Backup / Restore EFS partition (IMEI) on Galaxy S6&S6 Edge

If you own a Samsung galaxy S6 or galaxy S6 Edge with root access installed, its highly recommended to take a backup of your device’s EFS partition because this partition is the most sensitive system image on your device.

What is the EFS partition?
EFS is a very sensitive system partition that contains Phone specific information such as the IMEI, wireless devices MAC addresses, product code, and much more.

Why should you backup EFS partition?
because if it get corrupted you will stuck in a problem with your network connection (you will not be able to make/receive calls, send/receive messages, surf the internet using mobile data, …).

What is the main reasons of losing IMEI number?
1. Flashing a wrong custom ROM.
2. Flashing official firmware by Kies or Odin3 but usually it happened in downgrading process.

This post will guide you how to backup and restore EFS partition [IMEI] on galaxy S6 and galaxy S6 edge all models (International, AT&T, Verizon, T-Mobile, Sprint, Canadian, …) using Terminal emulator Application.

Requirements:

• Rooted galaxy S6 / S6 Edge.
• Terminal emulator App installed on your mobile.
• Enough free storage on your device (at least 50MB).

How to backup EFS partition for galaxy S6 and S6 Edge:

1. Launch Terminal emulator App
2. Type the following command then enter:
   su
   
3. Give terminal emulator root permission by taping Grant.
   
4. Type the following command then enter:
   dd if=/dev/block/sda3 of=/sdcard/efs.img
   
5. If everything goes fine, a backup file named “efs.img” will be created and saved into your device’s storage.
6. Save that file to your computer or to the cloud storage.

How to restore EFS partition for galaxy S6 and galaxy S6 Edge:

1. Place the file that you backed it up before “efs.img” into your device’s storage.
2. Launch Terminal emulator App.
3. Type the following command then enter:
   su
   
4. If it ask for root permission, hit Grant.
5. Type the following command carefully then enter:
   dd if=/sdcard/efs.img of=/dev/block/sda3
   
6. Type:
   reboot
7. After hitting enter, your device will reboot automatically.

Now you have done restoring your galaxy S6 and galaxy S6 Edge’s EFS apparition.

– Note that:
* Restoring [IMEI] EFS partition without backup file is NOT possible
* Restore EFS partition ONLY if your device’s IMEI number changed to NULL NULL, it doesn’t match with the number under the battery, or you can’t make call and your device display “Not registered on network”.