Owners of budget and mid-budget smartphones often face a lack of built-in space, and Xiaomi Redmi 9 is no exception to this rule: Built-in 32 or 64 gigabytes quickly fill up after installing messengers, social networks and a couple of games, which leads to a slowdown. Users are looking for ways to expand the usable area using a microSD slot, but the standard shell MIUI has its limitations in this matter.
The Android system on Xiaomi devices does not allow full installation of programs on an external drive for stability purposes. However, there are proven methods of transferring data, cache and even some applications that allow you to free up valuable megabytes of internal memory. In this article, we will analyze the technical details of the file system and provide a step-by-step algorithm of actions.
Before you start manipulating, you need to understand that not all programs support movement, and the speed of work. SD-The cards directly affect the speed of the installed software. Incorrect configuration can lead to startup errors, so it is important to follow the instructions clearly and use quality media.
Preparation of a memory card and choice of speed class
The first step is to purchase and properly prepare the media, as half of the success of the operation depends on its characteristics. Cheap low-speed memory cards can run even slower than a crowded internal memory of a smartphone, which will negate all efforts to optimize. For Xiaomi Redmi 9, it is recommended to use cards of the UHS-I Class 10 or higher, preferably from proven brands like SanDisk or Samsung.
Once the SIM card is physically installed in the slot, the system will prompt you to format the drive. It is important to choose formatting as a portable storage if you plan to use the card on other devices, or as internal memory if this option is available in your firmware version. In most cases, only the portable storage option is available on global versions of MIUI, which imposes certain restrictions on the installation of applications.
💡
Use a memory card adapter and a computer to pre-format to exFAT if your smartphone can’t read the card for a long time.
The formatting process completely destroys all data, so copy photos and documents to your computer or cloud storage beforehand. Once the procedure is complete, the system will create a hidden Android/data folder where the cached data of some games and programs will be downloaded. Without proper formatting, further migration actions will not be possible.
Configuring storage in the MIUI system
The MIUI shell interface may vary depending on the Android version and regional firmware, but the basic principles remain the same. First, you need to go to the settings menu and find the partition responsible for managing the device's memory, where the user sees detailed space statistics and can manage the connected drives.
Click on Settings item → The phone. → Storage or use the Security app → Cleaning to access memory management. In the window that opens, select yours SD-If the card is correctly defined, the system will display the free space and suggest basic actions, such as formatting or deleting files.
- 📁 Make sure that hidden files are displayed in the display settings to see system folders.
- 🔒 Check if the card encryption is installed, which may prevent reading data after a reboot.
- ⚡ Activate high performance mode in battery settings before moving large amounts of data.
Some firmware versions offer Adoptable Storage, which allows you to combine internal memory and map into a single space. If your Redmi 9 supports this option (often hidden in the engineering menu or available through ADB), this will be the perfect solution to the problem of space shortage, but it is worth remembering that once you activate this feature, you will not be able to extract the card and read it on another device without losing data.
☑️ Pre-transfer check
Methods of transferring applications to an external drive
The standard Android mechanism allows you to transfer only a part of the application data, not the entire executable file in its entirety. → Annexes → All applications, select the desired program and find the Change or Move button to SD-If the button is active (not grey), you can safely transfer the heavy elements of the program to an external medium.
However, many modern applications, such as WhatsApp, Instagram or bank clients, block this feature for security purposes, in such cases, the use of special utilities or commands through USB debugging helps. For example, the App2SD application can analyze the system and show which programs can theoretically be moved and which require root rights.
⚠️ Warning: After transferring the application to the memory card, it may load longer than usual on the first run. Do not delete the memory card while the phone is on, otherwise system services may terminate with an error.
There is also a method of using the sm (storage manager) command via USB debugging, which allows you to forcibly move data. To do this, you need to turn on the developer mode, activate the debugging and connect the smartphone to the computer. Through the ADB console, you enter the adb shell sm set-force-adoptable true command, after which the option of using the card as internal memory will appear when formatting the card.
Risks of using the sm set-force-adoptable command
Working with multimedia and application cache
Even if you can't fully install the program on the map, you can save a lot of space by transferring heavy media files and cache. Messengers like Telegram and Viber allow you to change the way you save downloaded files in your internal settings. Go to the chat settings and specify the folder on the map. SD-map to save photos and videos.
For cameras and voice recorders, the default save path can also be changed in the settings of the app itself. Open the camera, tap the settings gear, and select Save on SD-This automatically sends all new images and videos to an external drive, freeing up the internal space for the system to operate.
Browser and navigator cache (e.g. Google Maps or Yandex.Navigator) takes up gigabytes of space. These apps often have a "Storage" or "Cache" option where you can select an external map. If you don't have one, you can use the file manager to move Android/obb and Android/data folders, but you need to do this with caution, closing the applications beforehand.
💡
Transferring cache and media files is more efficient and safer than trying to transfer the application executables themselves.
Using File Managers to Organize Data
The standard MIUI Explorer is a good fit, but for deep file system work, it’s better to install a third-party manager, such as Total Commander or FX File Explorer, which allows you to see hidden folders, edit access rights, and safely move files between memory partitions.
When working with system folders, it is important to follow the directory structure. If you are migrating game data, make sure that the obb or data folder is created at the root of the map or in the corresponding partition of Android. Violation of the path structure will lead to the fact that the application will not find its resources and will require rebooting.
Regularly review the contents of the memory card, removing the remnants of remote applications. Over time, there are many “junk” folders that take up space but do not carry a payload, and the file manager will help you visually assess which folders take up the most space.
| Type of data | Recommended seat | Impact on speed |
|---|---|---|
| Photos and videos | SD-map | Low (depending on the class of the card) |
| Cash games (OBB) | SD-map | Medium (possible twitching) |
| System applications | Internal memory. | High (critical for speed) |
| Documents/Music | SD-map | Low. |
Possible problems and ways to solve them
In the process of memory optimization, users of Xiaomi Redmi 9 may encounter a number of common errors. Often, there is a situation when after transfer, the application stops starting or crashes immediately after opening, this indicates that the program does not work correctly with the external address space or the memory card has a low response rate.
Another common problem is the disappearance of widgets from the desktop. Widgets are often tied to the physical location of the application file, and when you change the location, the link can be terminated, in which case the widget must be removed from the desktop and added again from the widget menu.
⚠️ Warning: If the phone starts to run slower after transferring data, return the files back to internal memory. The low speed of writing the card can create (bottleneck) for the entire system.
If you have a card reading error, try to remove it, wipe the contacts, and paste it again. If the problem persists, check the card on your computer using the SD Memory Card Formatter utility. A damaged file system is a common cause of Android failures when trying to access application data.
💡
To diagnose memory card problems, use the SD Insight app, which will show the real write speed and originality of the drive.