In the following practical guide , supported by a video , I will teach you in a detailed and simple way how to back up the EFS folder on your Android device.
This folder is essential for the proper functioning of our Android system. For any user with a rooted device , creating this backup is one of the first mandatory actions, especially if you're a flashing enthusiast and frequently change ROMs on your device.
Why is it so important to back up the EFS folder?
The EFS partition contains critical and unique data for each device. Among the most important information is the radio configuration , which includes non-transferable data such as the IMEI (International Mobile Equipment Identity) number . If this data is corrupted or erased during a flashing process, the phone could become unusable , losing the ability to connect to mobile networks, make calls, or even access internal storage, displaying a null IMEI or one composed of zeros.
Prerequisites for obtaining a copy of the EFS folder
To proceed with the backup, it is essential to meet the following requirements:
- Having a rooted terminal to have access to system files.
- Have installed a file explorer with root permissionsSome recommended options are Root Explorer o ES File Explorer, both available in the Play Store.
Methods for backing up the EFS folder
Depending on the tools you have installed, there are several ways to achieve this backup:
1. Using Root File Explorer
This method involves navigating to the /efs directory using your chosen file explorer. Once there, copy the entire folder and paste it into your phone's internal storage or an external SD card. Finally, it's recommended to move this file to a secure location outside of your phone, such as a hard drive , USB drive, or your computer.
2. Through Modified Recovery (TWRP or CWM)
If you use a custom recovery, the process is more straightforward:
- In TWRP: Go to the menu BackupThere you will find a specific box to select the EFS partitionCheck the box and run the backup. (Note: Versions prior to 2.6.3.2 may not have this direct option.)
- In CWM Recovery: A specific ZIP file must be used (such as the LG_G2_Backup_EFS.zip (in the case of LG G2). It is installed using the option Install zip from sdcard, selecting the file and confirming.
After creating the backup, it's vital to verify that the file has been correctly generated in the /sdcard/EFS_Backup/ path or your chosen destination folder. For maximum security, upload the file to cloud services like Dropbox or Google Drive.
Other backup and restoration options
To restore the backup, simply place the ZIP file on the SD card and flash it from Recovery. Also, remember that tools like MyBackup exist for general data backups, although the EFS folder requires more technical handling due to its system nature.
In the video tutorial above, I explain in detail the step-by-step process to execute this procedure without errors.
More information – Requirements for flashing a custom ROM on Samsung devices, How to root your Android device with SuperOneClick
Download – Root Explorer , ES File Explorer
Securing the EFS partition is the most critical step before any deep system modification. By backing up the IMEI and network data to external storage or the cloud, you ensure your device can regain its original connectivity in the event of a catastrophic failure during a new ROM installation.
