How to combine SD card with internal memory on Xiaomi

Xiaomi and Redmi smartphone owners often face a lack of built-in storage, especially in budget models where storage is limited to 32 or 64 gigabytes. Built-in memory is quickly filled with system files, cache of popular applications and updates, which leads to slowdown of the device and the inability to install new programs. SD-card with internal drive in a single logical section.

Unfortunately, the shell MIUI By default, it hides this possibility by forcing the user to store media on an external medium and applications in internal memory. ADB-The process requires care, as incorrect actions can lead to data loss or unstable operation of the Android operating system.

In this article, we will discuss the technical aspects of memory integration, assess the risks and provide a step-by-step algorithm for different versions of firmware. It is important to understand that once combined, the memory card will be formatted into a special file system and can not be read on other devices without back-formatting.

Adoptable Storage on MIUI

Adoptable Storage, which first appeared in Android 6.0 Marshmallow, allows the system to view an external drive as part of internal storage. Unlike the standard mode, where only photos and videos can be transferred to the card, it installs the applications themselves and their data. On Xiaomi devices, this feature is software blocked by developers, presumably due to concerns about the speed of cheap memory cards.

For successful implementation, the memory card must meet certain speed standards, usually Class 10 or Class 10. UHS-I. Using slow cards will cause the system interface to respond with a delay, and applications will be launched longer. ext4 or f2fs, which is the native format for the Linux kernel on which Android is based.

The process of combining creates a new encryption section tied to a unique identifier for a particular smartphone, which means that you can't remove the card and paste it into another phone without losing data, and the system will require formatting, so the card becomes an integral part of the hardware of a particular Mi or Poco device.

⚠️ Warning: Before you start any manipulation of memory partitions, make sure that the battery is at least 60%. Interrupting the formatting process can damage the boot sector and not be able to turn on the smartphone.

There are two main activation methods: through the ADB debugging console without superuser rights and through special applications with Root rights. The first method is more secure for device warranty, since it does not require unlocking the bootloader, although in some cases it requires unlocking it for full access.

Preparation of equipment and software

Before you start modifying the memory structure, you need to prepare the workspace and tools, you need a computer running Windows, macOS or Linux, and a high-quality computer. USB-A cable that can transmit data, not just charge the device, and a smartphone should have a high-quality memory card of 16 GB, although for comfortable work it is recommended to use drives from 64 GB and above.

You need to install Xiaomi drivers and Platform-tools (ADB and Fastboot) on your computer, which let you send commands directly to your phone’s operating system, and you’ll need to turn on the developer mode on your smartphone to activate USB debugging.

It is important to make a full backup of all important data, as the process of combining involves a full formatting of the memory card. All photos, contacts and documents will be deleted without the possibility of recovery by standard means.

Checking for errors is another important step: use Android built-in tools or connect the card to your PC through a card reader and run a file system check. The presence of broken sectors can lead to a cyclical reboot of the phone after inserting the card into the system partition.

Activation through ADB without Root Rights

The most common and relatively safe way is to use the ADB command line. This method does not require unlocking the bootloader or obtaining superuser rights, which retains the device warranty in most cases. First connect the smartphone to the computer and make sure that the phone has a confirmation of connection and debugging.

Open the command line in the folder with the installed tools Platform-tools and enter the command to check the connection: adb devices. If the list appears device with a serial number, then the connection is established correctly. Then you need to enter the interactive shell mode by entering the command adb shell.

The key is to find your memory card ID, and to do this, type in the sm list-disks command, and the system will return a list of the connected drives, usually in disk:179.64 or similar format, and write down these numbers, as they will be needed for the next command.

adb shell sm partition disk:XXX,XX private 100

Instead of disk:XXX,XX, substitute your ID. 100 means that 100% of the card size will be given to internal memory. If you want to leave some space for normal file storage, you can specify, for example, 50, but for maximum effect, it is recommended to use the entire volume. After completing the command, the phone can restart or hang on the Mi logo for a few minutes - this is normal behavior when rebuilding partitions.

Use of Root Rights and Specialized Applications

For users who have already unlocked the bootloader and installed SuperSU or Magisk rights, a more flexible method of memory management is available. There are applications such as SD Maid or specialized scripts that automate the partitioning process. However, even with root rights, the process remains risky.

If you have root access, you can edit the system configuration files, forcefully including Adoptable Storage support in the settings menu. device.xml or similar system settings where the parameter changes force_adoptable After changing and rebooting, a regular button "Use as internal storage" may appear in the memory card menu".

The advantage of the root-rights method is the ability to fine-tune and, if necessary, roll back changes through the restoration of TWRP. If after manipulation the phone stopped booting, you can go to the recavators, mount partitions and delete the created script or restore the original configuration file from the backup.

Importantly, newer versions of MIUI 12, 13, 14 and HyperOS have tightened their security mechanisms, and some ADB commands can be ignored without obvious errors, creating the illusion of success. In such cases, the only working option is to flash the device to a global version or use custom firmware such as LineageOS or Pixel Experience, where this feature is often unlocked by default.

Application portability and data management

Once the memory is successfully combined, the system will start to perceive the card as an extension of the internal storage, but the applications will not be automatically transferred immediately. You will need to manually initiate this process for each heavy application. Go to Settings → Applications → All applications, select the desired program and find Memory.

If the function is working correctly, there will be a button "Change" or "Move to" SD-The card (which is now part of the internal memory) press it and confirm the action, the system will start copying the application files and its data to a new partition. The speed of the process depends on the size of the application and the speed class of your memory card.

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Not all applications support movement, and some banking applications may block the transfer for security or stability reasons.

Note that cache and some temporary files may still take up space in the original internal memory section if the application is not optimized to work with external drives. Periodic cache cleaning through settings or third-party utilities will help keep the system on top.

When you delete applications, you now have space on the combined memory pool, and you see a single space in the file manager, and the system will decide where to write the new file, based on the available location and Android distribution algorithms.

Possible problems and ways to solve them

One of the common problems is cyclic reboot immediately after the card is implemented. This can happen if the memory card has a low read/write speed or damaged sectors. The system tries to read critical application data, fails to time and reboots. The solution is to extract the card and load in safe mode or through TWRP to remove the problem partition.

Another problem is the disappearance of photos and media files from the gallery. Since the card is now formatted in ext4, the computer may not see files directly when connecting via USB. You need to use MTP mode, but it can also work unstable.

⚠️ Warning: If after memory is combined, the phone starts to heat up a lot in the area of the camera module or processor, immediately remove the memory card. Constant background recording of logs or cache on a slow card creates an excessive load on the power controller.

Users also often experience a card binding that flies off after updating the firmware, requiring the card to be formatted again, which will result in the loss of all data on the card. To avoid this, it is recommended to do a full backup of the data partition before updating the MIUI or temporarily return the card to portable storage mode if such an option is available without loss of data (which is rare).

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The stability of the combined memory depends on the quality of the memory card, and savings on the drive in this case will lead to a degradation of the performance of the entire smartphone.

Reverse process: return to factory settings

If you've decided to give up the idea of memory integration or sold a card, you have to return it to its original state. You can't just remove the card -- it won't read on any device. You need full formatting. Go to the storage settings, select your card, and click "Clean" or "Format as portable storage."

This process will destroy all data, including the installed applications. If you want to get it back to the past, the system will suggest that you move it back to internal memory after formatting, but it will take a considerable time. In some cases, especially with root methods, you may need to reset your phone to the factory settings (Wipe Data) to completely clean the configuration files.

Once back in normal mode, the card will be available for reading on PCs and other phones again, but will be completely empty.This is the standard behavior of Android security technology, which protects user data from theft when you lose your device.