SD card as internal memory Xiaomi: expand the storage correctly

Owners of Xiaomi, Redmi and POCO smartphones often face a shortage of built-in storage, especially on budget models with 32 or 64 GB of memory. MIUI system and HyperOS shell require considerable space to work, and modern applications take up more space. In this situation, buying a microSD card seems to be the obvious solution, but standard mode often does not allow you to install programs on it.

Fortunately, there's a way to turn an external drive into a full-fledged extension of the system partition, a process called Adoptable Storage, which, unlike just transferring photos, integrates flash memory into the logical structure of Android, allowing the system to perceive it as a native partition. However, before you start manipulating it, you need to understand that the SD card will be formatted and all the data on it will be irretrievably lost.

Implementing this feature on Xiaomi devices has its own peculiarities, as the manufacturer often hides this option in the standard interface. You will need not only a high-quality memory card of the UHS-I class or higher, but also, possibly, activating hidden settings through ADB or special utilities. It is important to be aware of the risks: using a slow card can slow down the entire smartphone.

Technical requirements and choice of memory card

Before you start setting up, it is critical to choose the right medium. Turning a card into internal memory means that the system will constantly read and write system files, application cache and databases to it. Conventional cards designed to store photos may not withstand this load and quickly fail or start to slow down the interface.

Note the Class 10, U3, and A1 (or A2) labels. The Application Performance Class (A1/A2) index is the most important parameter for this task, as it guarantees the minimum speed of arbitrary data access, which is critical for running applications. Maps without this index can cause lags even when opening simple programs.

It is recommended to use products from proven brands such as SanDisk, Samsung or Kingston. Cheap counterparts with AliExpress often have real capacity less than claimed and low write speed, which will lead to Android database errors.

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Buy memory cards only in official stores or large electronics networks. There is a very high proportion of counterfeits in the electronics market that can damage your smartphone's power controller.

The map size also matters. For comfortable work as a system partition, it is recommended to use a drive of at least 64 GB. A smaller volume will quickly fill up with system updates and messenger cache, negating the whole point of expansion.

Device preparation and backup

The conversion process requires a complete memory card cleanup. Android will create a new file structure and encrypt the data by linking it to a particular device. Once formatted, the card will not be read on other smartphones or computers without re-formatting.

Before starting the procedure, be sure to remove the card from the device and copy all important photos, documents and videos to your computer or to the cloud. Even if you plan to store data on the card, the current format may not be compatible with the new system partition.

Also, make sure that the smartphone itself has enough free space to perform system operations. Although the main load will fall on the external drive, data buffering requires internal memory resources.

⚠️ Note: After formatting the card as internal memory, it will not be possible to remove it without losing data and stopping applications.

Standard Method through MIUI settings

In some versions of the MIUI shell and HyperOS, Adoptable Storage is available out of the box, although hidden in the depths of the menu. First, insert the memory card into the slot and wait for the system to determine it. Go to Settings menu → About phone → Storage.

If you are lucky, you will see the item "SD-You can click on it and find the option "Format." In the process, the system can suggest you to choose the type of use: "Portable storage" or "Internal storage.

However, in most modern Xiaomi models, this item is hidden software. SD-To avoid users complaining about low-speed low-end models with cheap cards, if there is no storage type selection, you will need to use the card. ADB (Android Debug Bridge).

Don't worry if the standard method didn't work. It's the standard behavior of the system to ensure stability, and moving to the next section will get around that limitation in a software-based way.

Activation through ADB: step-by-step instructions

To activate the hidden function, you will need a computer (Windows, macOS or Linux) and installed ADB drivers. First, turn on USB debugging on your smartphone. To do this, go to Settings → About phone and quickly click on "MIUI Version" or "OS Version" 7 times until the message "You became a developer" appears.

Then go to Settings → Advanced Settings → For developers and activate the USB Debugging Toggle. Connect your smartphone to your computer with a cable. On the phone screen, you'll see a request for debugging permission — click "Allow."

Open the command line on your computer in the ADB tool folder and enter a command to check the connection:

adb devices

If a device with device status appears on the list, the connection is successfully installed. Next, you need to know the ID of your memory card.

adb shell sm list-disks

You'll get a disk ID, like disk:179.64, and write it down exactly, and you'll need it for the next command, and you can start the formatting process.

Formatting and integration of the drive

The most important step is to execute the formatting command, which will turn the card file system into an encrypted partition of Android, and be very careful when you type in the disk ID.

Use the following command design where XXX,XX is your disk ID:

adb shell sm partition disk:XXX,XX private 100

The private option tells the system to use the card as a private (internal) storage. The 100 number means that 100% of the card volume will be given to applications and data. Once you enter the command, the process will take from 30 seconds to several minutes.

Once the command is successfully executed, the smartphone can automatically restart, and in the storage, you will see that the total amount of internal memory has increased, and now the system will decide which applications and data to move to the new partition.

⚠️ Warning: Do not interrupt the formatting process or disconnect the cable while executing a command.This can damage the partition table and lose access to the map.

Application portability and data management

Once the map is integrated, the system doesn't always transfer all the applications immediately. You have to manually manage this process. Go to Settings → Apps → All apps. Choose a heavy application, such as a game or a social network.

Click on "Memory" or "Storage." If the app supports portability, it will show a button called "Change" or "Move." Select SD-Note that system applications and some Google services will not be able to move - this is a security limitation of Android.

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Not all applications can be completely moved to SD-Some of the data (especially widgets and services) will always remain in the internal memory of the smartphone to ensure stable operation.

To manage files, use the built-in MIUI Explorer or install Files by Google. When saving files in applications (for example, in messengers), you can now choose the default location of the save by default. It is recommended to configure automatic cache cleaning, since the write speed to the card is still lower than on the built-in UFS drive.

Check the status of the card regularly. The storage menu may show wear or read errors. If the smartphone starts to work slower, try restarting the device or checking the card for errors through the PC.

Possible problems and ways to solve them

The problem with using a map as an internal memory is that it's faster than you can use cheap media, and if you notice that animations are twitchy and apps take longer to open, you may have lost speed or not up to speed.

Another problem is that you can't use the card on other devices, so if you buy a new phone, you can't just rearrange the card, you can't just encrypt the data with the keys of the old smartphone, and you have to format the card to use it on the new device, and you've lost all the data.

It is also possible that after updating the MIUI firmware, the system stops seeing the partition on the map, in which case it helps to reconnect via ADB or completely reset the smartphone settings (with a pre-backup).

⚠️ Attention: When you use a card actively in internal memory, it consumes its rewrite life faster. Memory cards have a limited cycle of overwriting cells. 1-2 The map may need to be replaced.

However, for devices with a small amount of internal memory, this is the only way to comfortably enjoy modern heavy applications without constantly struggling for space.