Data loss or unsuccessful system update is the nightmare of any smartphone owner. Imagine that after installing a new version of the OS, the device stopped booting, turning into an expensive brick. It is at such moments that users understand that firmware backup is not a whim, but a necessity. Creating a full system image allows you to instantly restore the functionality of the gadget to the state it was in before the failure.
The backup process may seem complicated to a beginner, but in fact there are several proven methods available to everyone. From cloud services that save contacts and photos to deep cloning of system partitions via recovery. The choice of a specific method depends on your goals: do you just want to save data or are you planning to experiment with custom firmware.
In this material we will analyze in detail all the available methods, their pros and cons. You will learn what tools you will need, how to properly prepare the device and how to avoid fatal errors. A full copy of the firmware (Nandroid backup) includes all memory sections, which allows you to restore the phone to a bit-for-bit state. Let's start with basic preparation, without which further actions are impossible.
Preparing the device for backup copying
Before you start creating a system image, you need to perform a number of preparatory steps. Ignoring these steps may result in data loss or failure of the recording process. First of all, make sure that the battery charge is at least 60-70%. The process of copying large amounts of data is energy-intensive, and a sudden power outage can damage the file system.
Next, free up enough space on the external storage device. The firmware image can take from 4 to 16 GB depending on the amount of internal memory and installed applications. It is recommended to use a high-quality memory card MicroSD with a high speed class or connect your smartphone to a computer.
⚠️ Attention: Before starting any manipulations with system partitions, be sure to remove the SIM card and memory card if they are not used as target storage. This will prevent them from being accidentally damaged or formatted if the script fails.
It is also critical to enable USB debugging mode if you plan to use computer utilities. To do this, go to Settings → About phone and click on the build number 7 times to activate the developer menu. Then in the section that appears For developers activate the item USB debugging.
☑️ Preparing for backup
Usage built-in tools and cloud services
The simplest, although not the most complete, way to save data is to use standard functions Android. Modern shells from MIUI, OneUI or ColorOS offer powerful tools for local backup. They allow you to save a list of applications, system settings, call logs and messages.
To create such a copy, you usually need to go to the Settings → Advanced settings → Recovery and resetsection. Here you will find the local backup option. The process is fully automated, but it has a significant drawback: it does not save the operating system itself and system partitions.
- 📱 Saves desktop settings and icon locations.
- 💬 Archives history correspondence in instant messengers (if you have rights).
- 📞 Copies the phone book and call logs.
- ⚙️ Saves the settings of Wi-Fi networks and bluetooth connections.
For full synchronization with the cloud, you should use an account Google. This will ensure the safety of contacts, calendar and photos via Google Photos. However, remember that this is not a copy of the firmware in the full sense of the word. Restoration will take time and will require a stable Internet connection.
Use the "Restore Point" feature in Google One settings, if available for your model. This will create a snapshot of the system state before major updates.
Creating a full backup via TWRP Recovery
The most reliable method of creating a full copy of the firmware is using custom recovery TWRP (Team Win Recovery Project). This tool allows you to create a so-called Nandroid Backup, which is an exact copy of all sections of the internal memory. To use this method, the bootloader must be unlocked on the device and the TWRP environment itself must be installed.
After booting into recovery mode (usually a combination of the power and volume buttons), go to the section Backup. Here you will see a list of available sections for copying: Boot, System, Data, Cust and others. It is recommended to select all available items so that the copy is as complete as possible.
⚠️ Attention: When selecting the Data section in TWRP, you may need to decrypt it. If you have set a screen lock (PIN code or pattern), enter it when you first start the recovery, otherwise the partition may remain unreadable.
Select the target storage: internal memory or SD card. Swipe the slider to start the process. Execution time depends on the amount of data and the speed of the drive; this may take from 5 to 20 minutes. Upon completion, you will receive a folder with the date and time of creation, containing all images of the partitions.
What to do if TWRP does not see the internal memory?
In some cases, after unlocking the bootloader, the internal memory is encrypted again, and the old recovery cannot read it. Try formatting Data (Format Data) in the Wipe menu, but this will delete all files from the phone.
Backup via computer and ADB
For advanced users who do not want to install a custom recovery, there is a method of using the toolkit ADB (Android Debug Bridge). This method allows you to pull data from the device directly to your computer via a USB cable. It is less convenient for creating a full system image without root access, but is great for backing up user data and some system settings.
Connect your smartphone to your PC and open a command line or terminal in the folder with installed ADB drivers. Make sure that the device is detected by the command adb devices. To create a backup copy of applications and their data, use the following command:
adb backup -apk -shared -all -system -f backup.abA request to confirm the backup will appear on the phone screen. Enter the password to encrypt the backup (or leave it blank) and click the confirm button. The file backup.ab will be saved on your computer. Please note that this method does not copy partitions boot or recovery.
If you have root accessthe capabilities of ADB are expanded. You can use the dd shell command adb shell to copy specific partitions sector by sector. This requires accurate knowledge of the names of block devices (for example, /dev/block/mmcblk0p15), a mistake in which is fatal.
Comparison of backup methods
Choosing the right tool depends on your technical skills and the end goal. Below is a comparison table that will help you decide on the method. Each approach has its own limitations and areas of application.
| Method | Copy completeness | Complexity | Root required |
|---|---|---|---|
| Google Backup | Partial (data) | Low | No |
| Local backup MIUI/OneUI | Medium (applications + settings) | Low | No |
| TWRP (Nandroid) | Full (entire system) | Average | Desirable |
| ADB Backup | High (data + apk) | High | No (for systems) |
As can be seen from the table, TWRP remains the uncontested leader for those involved in modding. For ordinary users, a combination of built-in tools and the cloud is most often enough. However, if you plan to install custom kernels or firmware, a Nandroid backup is required.
TWRP is the only method that allows you to restore your phone to working condition even if the Boot partition is damaged.
Restoring firmware from a backup
Creating a copy is only half the battle. It is important to understand how to use it in a critical situation. The restaurant process directly depends on the method used. To restore from TWRP enough to boot into recovery mode, select Restore, specify the desired backup folder and confirm the action.
When using ADB recovery is performed by the command adb restore backup.ab. The device will ask for the password you set when creating the copy and begin the data recording process. At this time, the screen may go dark or flicker - this is normal behavior.
⚠️ Attention: Never try to restore a backup made on one phone model to another model. Even if the devices are from the same manufacturer, the memory partition structure may be different, which will lead to irreversible damage to the hardware.
If recovery via TWRP fails, try clearing the cache and Dalvik Cache before trying again. Sometimes an application version conflict prevents the image from deploying correctly. If the system does not boot after restoring, you may need to flash the stock image via Fastboot.
Keep backup copies of the firmware not only on your phone, but also on your computer or external hard drive. In the event of a physical breakdown of the smartphone, the memory card may be inaccessible.
Frequently asked questions (FAQ)
Is it possible to restore a TWRP backup to another version of Android?
It is extremely difficult to restore a system backup (System and Vendor sections) made on one version of Android to another version recommended. This can cause driver and library conflicts, leading to an endless reboot (bootloop). The Data partition can usually be restored, but applications may not work correctly.
How much space does a full copy of the firmware take up?
The size depends on how full the internal memory is. An empty system takes up about 2-4 GB. If you have many applications installed and data saved, the backup size can reach 10-15 GB or more. Always have some free space on your drive.
Is it safe to make a backup without unlocking the bootloader?
Without unlocking the bootloader, you will not be able to install TWRP, which means you will not be able to make a full Nandroid backup. Standard tools and ADB also work on locked devices, but they do not save the critical system partitions necessary for full recovery after a “brick”.
What to do if the backup process is frozen at 99%?
Do not turn off the device immediately. Wait 10-15 minutes, sometimes it takes a long time to write the latest files. If the progress does not change for longer, you will have to force restart the phone. Most likely, the copy will be damaged, and the procedure will have to start again, perhaps with a different storage.
Do you need to encrypt the backup copy?
Yes, especially if you store the backup on cloud services or transfer it over the Internet. Encryption will protect your personal data, passwords and correspondence from prying eyes in the event of a file leak. TWRP and ADB support setting a password for the backup archive.