Owners of budget smartphones like the Xiaomi Redmi 9 often face a lack of built-in storage. 64 or 128 gigabytes are quickly filled with heavy games, messengers and photos, which leads to a slowdown.
Fortunately, modern versions of the shell MIUI And the Android operating system provides tools to work with external drives. USB-plug-in OTG, You can turn it into an extension of the device's internal memory, and it frees up precious space and keeps the smartphone running.
In this article, we will discuss in detail the process of setting up an external drive, you will learn how to format the memory card correctly, what are the limitations of the system, and how to circumvent the standard Android prohibitions for installing programs on an external medium. It is important to understand that without formatting as internal memory, porting most system applications is impossible.
Preparation of equipment and choice of storage device
Before you start software setup, you need to make sure that your hardware is compatible. Not any flash drive is suitable for emulating internal memory. Read and write speed is crucial: if the drive is too slow, the smartphone interface will slow down, and applications will load longer than usual.
For Redmi 9, USB 3.0 and higher flash drives are the best choice, with high random access speeds. Older USB 2.0 models are possible, but not recommended for heavy gaming or resource-intensive applications. You will also need a quality OTG adapter cable that provides stable power to the connected device.
- 🔌 USB-flash drive from 16 GB (preferably 32 GB or 64 GB) with a write speed of at least 20 MB / s.
- 📱 Cable adapter OTG Micro-USB or Type-C connector (depending on your Redmi 9 modification).
- 💾 Backup of data from the flash drive, as the setup process will require its complete cleanup.
Note the file system of your drive. By default, flash drives are often formatted in FAT32 or exFAT. To work as internal memory, Android will require you to change the partition structure to ext4 or a special encrypted circuit, which means that all data on the media will be permanently deleted during the setup process.
⚠️ Note: In the process of configuring the flash drive as internal memory, it will be formatted and encrypted, and then you can’t use it on other devices (PCs, TVs) without re-formatting, which will delete all data again.
Basic setting USB-storage MIUI
The first step is to connect the external device to the smartphone correctly. Insert the flash drive into the OTG adapter and connect it to the Redmi 9 charging connector. The system must automatically identify the new device and issue a corresponding notification in the notification curtain. If this does not happen, check the operability of the cable and the flash drive itself.
Go to the smartphone settings to make sure that the mode USB-The drive is activated correctly, depending on the version. MIUI, The path may vary slightly, but it's usually in the optional settings menu, and here you'll see information about the connected device and its current volume.
Click on your flash drive name in the list of storage devices. The system will offer several use cases. For our purposes, standard use as portable storage will not work, because it only allows you to store media files. We need to change the status of the drive to "Internal storage".
If the system doesn't offer the formatting option as internal storage right away, it means activating the hidden feature through the developer menu is required. Xiaomi's standard settings often hide this opportunity for inexperienced users to avoid errors.
Activation of Developer Mode and Hidden Functions
To access the advanced memory management settings, you need to activate the developer mode, which is standard for Android devices, allowing you to make deep changes to the configuration of the system. Don't worry, it's safe if you follow the instructions.
Open the Settings app and go to About Phone. Find the MIUI version and quickly click on it 7-10 times in a row. After a few clicks, a pop-up message will appear that you have become a developer. Now a new item will appear in the settings menu.
Go back to the main settings menu and select Additional (or Advanced Settings) and you will find Developer's. Once you log in, scroll down to the section associated with the network or system and find the Default option to use external storage or Forced permission to write to the site. SD-map.
☑️ Activation of the developer mode
Activating this feature allows the system to perceive the external flash drive as an equal partner of internal memory. However, this may not be enough to fully transfer already installed applications, often requiring mandatory formatting of the drive itself through the command line or special utilities if the standard interface does not provide the necessary options.
⚠️ Attention: Enabling options for developers may affect the stability of some applications. If you are not sure about your actions, do not change the parameters, the value of which you do not know.
Formatting a flash drive as internal memory
The most important step is direct formatting. In the drive management menu (Settings -> Memory -> Your USB drive), select Format. The system will warn you about data loss and suggest you choose the formatting type: "Portable storage" or "Internal storage".
Choose the Internal Storage option. Android will create an encrypted partition on the drive that only your smartphone can understand. The process can take several minutes, depending on the recording speed and storage capacity. Do not interrupt the process or turn off the flash drive.
Once formatted, the system will suggest migrating existing data (photos, contacts, applications) to a new drive, and accept this suggestion to instantly free up space in internal memory, and now some of the system processes and new downloads will go to the flash drive by default.
| Parameter | Portable storage | Internal storage |
|---|---|---|
| File system | FAT32 / exFAT | EXT4 (encrypted) |
| Use on PCs | Maybe immediately. | Reformatting is required |
| Installation of applications | Limited. | Full support |
| Encryption | No. | Yeah (device binding) |
It’s worth noting that even after formatting as internal memory, not all applications allow themselves to be fully ported, and many app developers, especially Google’s banking and system services clients, prohibit moving their files to external media for security and stability reasons.
Why can't some apps be moved?
Application portability and data management
Once you have successfully set up, you can start moving applications. Go to Settings -> Applications -> All Applications. Select the program you want from the list. If portability is possible, you will see a Change or Memory button with the option to select storage location.
Click on the button and select External Storage (or the name of your flash drive). The system will start the data migration process. The transfer time depends on the size of the application. Major cache games (such as PUBG or Genshin Impact) can be delayed for several minutes.
Use standard MIUI Explorer or third-party file managers such as Total Commander or FX File Explorer to manage files, which allow you to manually move folders with game cache or heavy documents to a flash drive, freeing up internal space.
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For large cache (OBB) games, it is sometimes more effective to manually move the data folder to the root of the flash drive, creating a similar structure of Android/obb directories there, than to rely on automatic porting.
However, there is a caveat: When you delete an application, the data can stay on the flash drive, creating garbage. Periodically check the contents of the external drive through the file manager and delete the folders of remote programs, which will help maintain order and efficiency of disk space use.
Alternative methods and use of ADB
If standard MIUI methods do not allow you to migrate a particular application, you can use ADB (Android Debug Bridge) debugging, which requires connecting a smartphone to a computer and having basic command line knowledge, but gives you maximum control over the system.
To start, turn on USB debugging in the developer menu. Connect your phone to your PC and start the console. Using the adb shell pm get-install-location command, you can find out the current default installation location. Change it to external storage, you can command:
adb shell pm set-install-location 2Here, 2 stands for external drive, 0 for automatic system selection, and 1 for internal memory only. Once you've completed the command, try reinstalling or updating the application you want, and it should be installed on the flash drive.
⚠️ Attention: Teams ADB The value of external memory only (2) can cause errors if the flash drive is removed. Use the value of "0" (automatically) after the initial setup so that the system can decide where to put the applications.
There are also third-party utilities like Link2SD or App2SD that require root rights. On Redmi 9, obtaining superuser rights (Root) is possible through unlocking the bootloader and installing Magisk, but it is a complex process that deprives of warranties and can disrupt the operation of banking applications. For most users, regular formatting tools are enough.
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Using ADB is an advanced method for power users, and for standard memory expansion tasks on Redmi 9, it is quite enough to format a flash drive as internal storage.
Possible problems and solutions
It can be difficult to operate, and one of the common problems is that you suddenly turn off your flash drive or read errors, and this is often due to power shortages or overheating of the controller in cheap adapters. OTG. Try replacing the cable or using a flash drive with your own power (via USB-hub).
Another problem is slowing down the interface, and if animations get twitchy and apps open for a long time, then your flash drive is not fast enough to work as a system partition, in which case you should transfer only media files (photos, videos, music) to an external drive, and return the applications to internal memory.
It can also request error checks from time to time. Don't ignore those requests. Run a scan to prevent data loss. Regularly backing up important files to your cloud services (Google Drive, Mi Cloud) will protect you from a flash drive crash.