In this guide, we will show you the steps to backup the EFS Partition/IMEI Number on your Android device. While Samsung devices hold one of the biggest drawbacks in custom development [tripping of the Knox which cannot be reversed even if you relock the bootloader] but that hasn’t stopped the tech enthusiast from gaining administrative privileges and welcoming abode a plethora of tweaks onto their device.
However, Knox isn’t the only concerning factor here, there’s always an associated risk involved of EFP Partition getting corrupted. When that happens, you might face some network-related issues [which in most cases could be rectified by a modem or radio file] and more importantly, you will have to bid adieu to your device’s IMEI number. And for that, there’s no fix whatsoever.
Once it’s gone, then you might not be able to recover it ever again, thereby making your device completely useless. Therefore, it’s always a recommended approach to take a backup of the EFS Partition on your Samsung device beforehand. In case, if something goes wrong, then you could easily restore the backup and get back your IMEI number! So without any further ado, let’s show you how this could be carried out.
Table of Contents
How to Backup EFS Partition/IMEI Number on Android
- To begin with, root your Samsung device via Magisk patched AP/boot file.
- Then download and extract Android SDK Platform Tools on your PC.
- Now enable USB Debugging on your device and connect it to PC via USB.
- Then head over to platform tools, type in CMD in its address bar, and hit Enter. This will launch the Command Prompt.
- Now type in the below command to open the shell environment.
adb shell
- After that, execute the following command to invoke the SuperUser request
su
- You will now get a prompt on your device, tap on Allow/Grant.
- Now proceed with either the automatic [easier] or the manual method [lengthy], depending on your requirements.
Automatic Method
- Type in the below command in the CMD window to take a backup of the EFS partition
su -c dd if=/dev/block/bootdevice/by-name/efs of=/sdcard/Download/efs.img
- The efs partition will now be backed up in the Downloads folder on your device. It is recommended to transfer it to your PC.
Manual Method
- First off, type in the below command to bring the partition table of your device
ls -la /dev/block/by-name
- It will bring up the EFS Partition location, check out its sda address. In our case, it is /dev/block/sda9
- Now execute the below command to backup the EFS Partition [replace location accordingly]
dd if=location of=/sdcard/efs.img bs=4096
- In our case, the location is /dev/block/sda9, so the command will transform to:
dd if=/dev/block/sda9 of=/sdcard/efs.img bs=4096
- The backup will now be created in the Internal Storage. Make sure to transfer it to your PC.
How to Restore EFS Partition
- Transfer the persist.img file to the platform tools folder on your PC.
- Next up, connect your device to the PC via USB cable. Make sure USB Debugging is enabled.
- Now head over to the platform-tools folder, type in CMD in the address bar, and hit Enter.
- This will launch the Command Prompt. So type in the below command to boot your device to Fastboot Mode
adb reboot bootloader
- Finally, execute the below command to flash the efs.img file
fastboot flash efs efs.img
- That’s it. You may now reboot your device to the OS via the below command-
fastboot reboot
So these were the steps to take a backup of EFS Partition/IMEI Number on your Android device. If you have any queries concerning the aforementioned steps, do let us know in the comments. We will get back to you with a solution at the earliest.
