Xiaomi smartphone owners often face a lack of built-in space to install new apps or download media files. The built-in drive is quickly filled with messenger cache, high-resolution photos and heavy games. In this situation, a memory card slot comes to the rescue, which allows you to physically increase the amount of available storage.
But simply connecting a card doesn't always solve the problem, because Android stores app data in internal memory by default, and to make full use of the external drive to run programs, you need to combine partitions, which turns the card into an extension of the system partition, making it an integral part of the device.
In this article, we will discuss the technical details of the procedure, risks and step-by-step algorithm of actions. You will learn how to configure Adoptable Storage without losing data and why some models require a special approach.
Technical features of combining memory on Android
Function that allows for the connection SD-The card and internal memory, officially called Adoptable Storage, was embedded in Android 6.0 Marshmallow and allows the system to encrypt an external drive, making it available only for that particular device. After activation of this option, the card ceases to be just a portable file carrier.
Unfortunately, Xiaomi’s MIUI shell (and its successor HyperOS) often hides this feature from the standard settings menu, to protect the user from using slow cards that can slow down the entire system.
⚠️ Attention: The process of combining requires a complete map formatting, all files on it will be permanently deleted. Be sure to back up important documents before starting work.
There are two main approaches to solving the problem: standard formatting as internal storage (if the item is available) and forced activation through debugging over USB. The choice of method depends on the version of Android and the specific model of your smartphone.
Why is Xiaomi hiding this feature?
Preparation of equipment and selection of memory card
The success of the operation depends on the quality of the storage device used. In internal memory mode, high reading and writing speeds, especially random access (IOPS), are required. Conventional old cards may not pass the system's check or will work unstable.
It is recommended to use UHS-I or UHS-II cards with a speed class of at least 10. The best choice will be the models of the SanDisk Extreme series, Samsung EVO Plus or Kingston Canvas Go. Avoid buying cheap carriers of unnamed brands, as they often have understated real characteristics.
- 🚀 Speed: Minimum write speed should be 30 MB/s for a comfortable application.
- 💾 Volume: It is recommended to use cards ranging from 32 GB to 256 GB for optimal performance.
- 🛡️ Reliability: Choose water and heat protection cards as they will work in intensive mode.
Before installing, make sure that the tray for SIM-In some budget models Xiaomi uses a hybrid slot, where in the second compartment you can install either a second SIM-card or memory card, but not simultaneously.
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Check the memory card on your computer before installing it on your phone using the h3testw utility. This will help identify broken sectors and the real storage capacity.
Activation of the developer mode and debugging
To force the memory merge function to be enabled, you need to access hidden system settings. The first step is to activate the developer mode, which is a standard procedure for Android devices to make changes to system settings.
Open the Settings app and go to About Phone. Find the MIUI Version (or OS Version) bar and quickly click on it 7-10 times in a row. Once you have become a developer, you can proceed to set up the debugging.
Settings → Additional settings → For developers → Debugging by USBTurn on the USB Debugging switch. The system will issue a security alert, confirm the action. Now your smartphone is ready to interact with the computer or terminal to enter system commands. Without this step, no further manipulation is possible.
Instructions for formatting through ADB
The most reliable way to connect memory is to use tools. ADB (Android Debug Bridge. You will need a Windows computer, USB-This method works even if the settings menu does not have the option "Use as internal storage".
Connect your phone to your PC by inserting a memory card beforehand. Open the command line on your computer in the ADB folder and type a command to check the connection. If a window appears on your phone asking for debugging permission, be sure to tick "Always Allow" and click "OK."
☑️ Checklist before formatting
To start the formatting process, use the following command in the terminal:
adb shell sm partition public,16:128 mixedIn this command, the numbers are the percentage ratio. For example, 16:128 means that 16% will remain portable storage, and 128% (conditionally, the rest) will be given to internal storage. You can change the proportions depending on your needs, for example, 50:50.
Once you input the command, it takes a few minutes. Don't turn off the cable or touch the phone. When you complete the operation, the system will restart or suggest restarting the device. Once you turn on, the card will be defined as part of the internal memory.
Comparison of data storage methods
Understanding the difference between memory card modes is critical to system stability, and users can choose between two options: use as a portable medium or as internal storage, each with its advantages and limitations.
| Characteristics | Portable storage | Internal storage (Adoptable) |
|---|---|---|
| Availability of data | Available on any device | Only on this phone (encryption) |
| Installation of applications | Limited or impossible | Full installation support |
| Speed of operation | Depends on the card. | Optimized by the system |
| Security | The data can be read on PC | Data is not available without a phone |
If you change devices frequently or transfer files to your computer, portable storage may be more convenient, but internal storage is the only solution to address the problem of lack of space under applications.
It's worth noting that when you choose the internal storage mode, the memory card is physically tied to a particular instance of the smartphone, and you can't extract it and paste it into another phone without losing data and resetting the settings.
Possible problems and ways to solve them
There may be errors in the process of combining memory "SD-This may indicate poor card quality, broken sectors, or file system incompatibility.
⚠️ Note: If the phone is slowing down after formatting or the apps are crashing, it may not be fast enough to work in system partition mode.
Use Xiaomi's built-in tools to diagnose. Go to Settings → About Phone → Storage and check card status. If errors repeat, try formatting the card on your computer in the exFAT or FAT32 file system before trying to merge again.
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The combined memory is 90% stable depending on the quality and speed of the microSD card you use. Don't skimp on this component.
Another common problem is the inability to port some system applications: This is an Android security limitation that prevents you from moving critical system components to an external drive, even if it is formatted as an internal drive.