Owners of smartphones of the Xiaomi, Redmi i POCO line often face a lack of built-in storage, especially when actively using the camera and installing heavy applications. The built-in memory fills up at an alarming rate, and the system begins to slow down, demanding free space. Fortunately, there is a powerful tool - Adoptable Storagethat allows you to combine a memory card with system storage into a single logical drive. This turns a regular flash drive into a full-fledged extension of the device’s internal memory.
However, the interface MIUI by default often hides this option, remaining true to a more conservative approach to using external drives. This article will examine in detail all the nuances: from preparing the media to forcing the function to be activated via ADB if the standard menu does not offer the desired choice. You will learn how to properly format a card to avoid data loss and ensure stable system operation.
It is important to understand that this process is irreversible for the data on the card itself. After formatting, all files on it will be deleted, and it itself will become unreadable for other devices without resetting. This is a fee for security and integration: the system encrypts the data, linking it to a specific smartphone. Let's take a step-by-step look at how to turn your microSD card into reliable storage for Android.
Preparing a memory card and choosing the right speed class
Before running into the settings, you need to make sure that your storage device can withstand the load of the operating system. When the SD card becomes part of the system partition, application caches, databases, and system logs begin to be written to it. Read and write speed is critical here. Using a slow card will cause the interface MIUI to freeze, and launching applications will take forever.
The minimum requirement is standard Class 10 or UHS-I. However, for modern smartphones with high-resolution screens and heavy applications, this may not be enough. The ideal choice would be cards marked A1 or A2 (Application Performance Class). These designations guarantee a minimum number of input/output operations per second (IOPS), which directly affects system responsiveness.
Pay attention to the storage capacity. The system Android imposes certain limitations, and the card must be spacious enough to justify its use as internal memory. It is recommended to use media with a capacity of 64 GB or higher. Smaller capacities will quickly fill up, and you will again be faced with the problem of running out of space, wasting time on setup.
⚠️ Attention: Do not use old or cheap memory cards from unknown brands in internal memory mode. They have a high risk of failure due to intensive cyclic rewriting, which can lead to the loss of all data and even malfunction of the smartphone.
Standard formatting procedure through MIUI settings
First of all, try using standard shell tools Xiaomi. In some versions MIUI and on certain models this function is available out of the box. Insert the card into the slot and wait for the notification. If the notification does not appear, go to the settings menu manually. The path usually looks like this: Settings → About phone → Storage or Settings → Advanced settings → Storage.
Find your SD card in the list of connected drives. Click on it to open the control menu. If your system supports the native extension, you will see a Format button. During the formatting process, the system can offer two options for use: “Portable storage” and “Internal memory”. You need to choose the second option. The system will warn you about wiping (complete deletion) of all data.
After confirmation, the smartphone will begin the formatting and encryption process. This may take from a few minutes to half an hour, depending on the size of the card. Do not interrupt the process or remove the card. Upon completion, the system will offer to transfer existing data (photos, media) to a new disk. Agree to instantly free up space in your internal storage.
Before formatting, be sure to copy all important files from the SD card to your computer, as during the setup process it will be completely cleared.
Forced activation via ADB: if MIUI hides the option
Sorry, engineers Xiaomi often block the ability to select the “Internal Memory” mode in the visual interface, leaving only the flash drive mode. In this case, we will need a computer and a utility ADB (Android Debug Bridge). This is a powerful developer tool that allows you to send commands directly to the Android system, bypassing shell restrictions.
First, you need to activate developer mode on your smartphone. Go to Settings → About phone and quickly click on the “MIUI Version” item seven times in a row until the activation message appears. Then go to Settings → Advanced settings → For developers and turn on the toggle switch USB debugging.
Connect your smartphone to your computer with a cable. The platform must be installed on the PC SDK Platform Tools. Open a command line or terminal in the folder with ADB and enter the command to test the connection:
adb devicesA request for debugging permission will appear on the phone screen - confirm it. If the console displays the serial number of the device with status device, then the connection is established. Next you need to find out the ID of your memory card. Enter the command:
adb shell sm list-disksThe system will return the disk ID, usually in the format disk:179,64 or similar. Remember or copy this number, you will need it for the next step.
☑️ Preparing to work with ADB
Format command and partition creation
The most crucial moment is executing the format command. We use the sm (storage manager) utility through the ADB shell. The command has a strict syntax and requires the disk ID obtained in the previous step. Be extremely careful when entering so as not to format the built-in memory of your smartphone by mistake.
Enter the following construction, replacing disk:XXX,XX with your real ID:
adb shell sm partition disk:XXX,XX privateThe parameter private indicates the system that the disk should be encrypted and used as internal memory. If you want to leave the option of using the card as a regular flash drive in the future (hybrid mode), you can use the parameter mixed indicating the percentage of space for applications, but the mode private provides the best integration.
After entering the command, the smartphone screen may go dark for a while - the process of creating partitions and encryption is in progress. Once complete, you will see a notification indicating that the drive is ready for use. Now in the storage settings the card will be displayed as part of the internal memory, and not as a separate volume.
⚠️ Attention: The command
sm partitionirrevocably deletes all data on the card. Make sure you select the correct drive ID (disk:...), otherwise you may accidentally erase data from the built-in drive if the system incorrectly identifies it.
What to do if the command gives the error "Failed to create filesystem"?
The error occurs frequently due to the fact that the card already has partitions or a file system that Android cannot repartition automatically. Try clearing the partition table with the command adb shell sm destroy disk:XXX,XXfirst, and then repeat the partition command. If this does not help, format the card in FAT32 on your computer using the standard Windows Disk Management tool, deleting all volumes, and try again.
Transferring applications and data management
After successful formatting, the system begins to perceive the card as a single unit with internal memory. However, this does not mean that all applications will instantly move to the new drive. You need to configure storage priorities. Go to Settings → Applications, select the desired application and find the "Storage" item. If the application developer has allowed the transfer, a “Change” or “Move to SD card” button will appear there.
Some system applications and critical services MIUI may remain on the built-in storage forcibly. This is normal and even necessary for stability. The bulk of user software, especially heavy games and social networks, can be safely sent to an SD card. This will free up precious gigabytes of fast built-in flash memory.
It is also worth setting up the camera and instant messengers. In the camera settings Xiaomi find the "Save to SD card" item and activate it. For WhatsApp and Telegram the path to the folder with media files can be changed in the settings of the applications themselves by specifying the path on the external drive (which is now part of the internal memory, but logically accessible).
| Parameter | Internal memory (eMMC/UFS) | SD card (Internal mode) | SD card (Portable mode) |
|---|---|---|---|
| Read/write speed | High (up to 1000+ MB/s) | Depends on the card class (up to 90 MB/s) | Depends on the card class |
| Encryption | Yes (hardware) | Yes (software, tied to the device) | No (or optional) |
| Transfer to another device | Impossible without resetting | Impossible (data cannot be read) | Possible immediately |
| Reliability | High | Medium (depending on the quality of the card) | High |
Even after transferring applications, some of their data (cache, updates) may remain in the built-in memory. This is an architectural feature of Android that cannot be completely bypassed.
Possible problems and ways to solve them
Using the card as internal memory is not without its drawbacks. The most common scenario is that the card suddenly turns off or a read error message appears. This can happen due to overheating of the card, poor contact in the slot, or poor quality of the media itself. In such cases, applications installed on the card will no longer launch, and the system will require re-configuring the drive.
Another problem is a decrease in the overall speed of the smartphone. If you installed a class card U1 instead of U3 or A2, the interface may begin to slow down when opening a menu or switching between tasks. In this case, the only solution is to replace the card with a faster model and then transfer the data.
Users also complain about accelerated wear of the memory card. Internal memory mode involves constant background recording of logs and cache, which significantly reduces the resource of memory cells compared to conventional photo storage. Regularly make backup copies of important data, since a sudden failure of the card in this mode means loss of access to all applications installed on it.
⚠️ Attention: If you decide to remove a card operating in internal memory mode without first “forgetting” the device in the settings, you will receive a mounting error. You can return the card to working mode only by completely formatting it, which will destroy all data on it.
Why do application icons disappear after removing the card?
:Applications are physically located on the memory card. When the card is removed or disabled by software, the operating system loses access to executable files (.apk) and application data. The icons can remain on the desktop, but when clicked, the system will report that the application is not installed. To restore, you need to insert the card back or reinstall applications into the internal memory.
Frequently asked questions (FAQ)
Is it possible to return the card to regular flash drive mode without losing data?
Unfortunately, no. The process of converting a card to internal memory includes encryption and changing the partition structure. To return the card to portable storage (flash drive) mode, it must be formatted through the settings (Settings → Storage → SD card → Format), which will completely delete all files.
Why is my 64 GB card displayed as 58 GB?
This is normal. First, card manufacturers use a decimal number system (1 GB = 1,000,000,000 bytes), while Android uses a binary number system (1 GiB = 1,073,741,824 bytes). Secondly, part of the space is reserved for service partitions, a file system table and an area for leveling out the wear of memory cells.
Will the card work on another Xiaomi phone?
No, if it is formatted as internal memory. Encryption keys are tied to a specific device (its unique ID). When you insert such a card into another phone, the system will prompt you to format it, since it will not be able to decrypt the data. To transfer data between devices, use portable storage mode or cloud services.
How can I find out the real speed of my SD card on my phone?
You can install special utilities from Google Play, for example, A1 SD Bench or CPDT. They will conduct a read and write speed test and show the result in MB/s. Compare the figures obtained with the declared characteristics of your card. If the write speed drops below 10-15 MB/s, the card is not suitable for internal memory mode.
Does the use of an SD card affect the warranty of the smartphone?
The mere use of a memory card and software formatting via ADB is not grounds for voiding the warranty. However, if, due to a low-quality card, physical damage to the slot or power controller occurs, the service center may refuse free repair, citing the use of incompatible accessories.