Owners of budget smartphones are often faced with a shortage of internal storage, and the model Xiaomi Redmi 9A is no exception. With only 32 or 64 GB of internal memory, the system and pre-installed services take up a significant portion of the space, leaving the user very little space to install new apps. When the storage is full, the device starts to work slowly, and installing updates becomes impossible.
Fortunately, this model supports installation of memory cards of format MicroSD up to 512 GB, which theoretically solves the problem of lack of space. However, the standard shell MIUI by default does not allow you to simply transfer downloaded applications to external media. This limitation was made by the developers to ensure system stability, since the speed of memory cards is often lower than the speed of the built-in storage.
Despite these difficulties, there are several proven methods to bypass standard restrictions and relieve internal memory. In this article, we will analyze in detail the standard capabilities of the system, hidden functions for developers and the nuances of formatting the drive, which will help you effectively manage the space on your Redmi 9A.
Preparing a memory card and choosing the right speed class
Before you start manipulating system settings, you need to make sure that your memory card meets the requirements of a modern mobile operating system. Using a slow or low-quality card may cause migrated applications to launch with a noticeable delay or even freeze during operation. For comfortable use, it is recommended to choose drives with a write speed of at least 10 MB/s.
Pay attention to the card markings: cards of the Class 10, UHS-I or V30class are best suited for installing applications. Older standards like Class 4 or Class 6 can handle storing photos and music, but they will become a bottleneck when running heavy apps. If you plan to actively use external storage for software, saving on this component will lead to a decrease in the overall performance of the smartphone.
Buy memory cards only from official dealers or large networks, as the market is overflowing with fakes that show the wrong amount in the phone settings.
Before installing it in the slot, make sure that the card contacts are clean and there are no visible damages. Insert the drive into a special tray Redmi 9Athat supports a hybrid configuration (two SIM cards or one SIM and one memory card). After physical installation, the system will automatically detect the new media and offer to configure it.
Standard MIUI capabilities: transferring media and documents
Immediately after installing the memory card, the operating system Android in the shell MIUI will offer to use it as portable storage. In this mode, you will not be able to transfer the application files themselves (.apk) and their data to the card, but you will be able to free up space by moving user content there. This is the first and safest optimization step that does not require deep intervention in the system.
To transfer files, use the standard file manager. Go to the Files → Internal shared storage section and select folders that take up a lot of space. Usually these are directories DCIM (photos and videos from the camera), Download (downloads from the browser) and Music. Select the files you want, click the "Move" button and select your SD card as the destination path.
☑️ Free up internal memory
Many modern applications, such as instant messengers and social networks, have their own media storage settings. For example, in Telegram or WhatsApp you can specify the path to save downloaded files in the settings. Redirecting data streams to an external drive allows you to save gigabytes of space on the internal memory without having to manually move files every time.
⚠️ Attention: When moving system folders or files required for running certain applications, make sure that you do not break the directory structure. Do not move the Android/data folders manually without understanding the consequences.
Activating developer mode for advanced settings
If standard file transfer is not enough, you can try to activate hidden system features through the developer menu. In some firmware versions MIUI this allows you to forcefully move applications that the developers have not prohibited from being moved. However, you should understand that this function is not a universal solution for all apps.
To access advanced settings, you must activate developer mode. Go to the menu Settings → About phone and find the item MIUI Version. Click on this item 7 times in a row until a notification appears indicating that you have become a developer. After this, a new section “Advanced” or “Advanced settings” will appear in the main settings, where there will be an item “For developers”.
Inside the developer menu, scroll down to the section related to applications. Find the option "Allow saving to external drives" (Allow saving to external storage) and activate the switch. This setting forces the system to offer the user a choice of installation location when downloading new apps from the store Google Playif the application supports such a function.
Why are not all applications transferred?
Even with the option enabled, many popular applications (banks, instant messengers) have a hard link to the internal memory in your code, and it is impossible to bypass this programmatically without root access.
After enabling this function, try reinstalling some non-critical application. During the installation process, the system may ask where exactly you want to install the app. If such a question does not arise, it means that a particular application does not support working with external media at the level of its code, and no phone settings will change this.
Formatting the card as internal storage (Adoptable Storage)
The most radical but effective method is to format the memory card as internal storage. This feature, known as Adoptable Storagewas introduced in Android 6.0 and allows the system to combine the physical SD card with the internal memory into a single logical space. In this mode, the card is encrypted and becomes an integral part of the system.
To activate this mode on Redmi 9A, go to Settings → Storage. Select your SD card, click on the three dots in the top corner or the "Storage Settings" button and select "Internal Storage". The system will warn you that all data on the card will be deleted, so be sure to back up your important files before starting the procedure.
| Option | Portable storage | Internal storage |
|---|---|---|
| Access from PC | Yes, via cable | No (formatting required) |
| App transfer | Limited or impossible | Full support |
| Encryption | No | Yes, binding to the device |
| Working speed | Depends on the card | Requires a high-speed card |
After formatting is completed, the system will automatically begin to transfer some of the data and applications to the new volume. You will be able to install apps with virtually no restrictions until the total capacity of the internal memory and card is full. However, it will no longer be possible to remove such a card and insert it into another phone or computer without losing data.
Formatting the card as internal memory makes it unique for a specific smartphone: if the phone is lost or broken, the data on the card will be impossible to read without a complex decryption procedure.
Using ADB for forced transfer
If the graphical interface does not allow desired result, you can use the debugging tool ADB (Android Debug Bridge). This method requires you to connect your smartphone to your computer and have basic knowledge of the command line, but it gives you deeper access to managing app packages.
First, you need to enable USB debugging in the developer menu we talked about earlier. Connect Redmi 9A to the PC with a cable and make sure that the computer sees the device. Open a command line on your computer in the folder with ADB installed and enter the command to get a list of installed packages:
adb shell pm list packages -fFind the desired application in the list and copy its full package name. To transfer a specific application to a memory card, use the command pm move-package. The command syntax is as follows, where instead package_name you need to insert the name of your application:
adb shell pm move-package package_name external⚠️ Warning: ADB commands may cause system instability when migrating critical system components. Use this method only for third-party custom applications that you installed yourself.
It is worth noting that even through ADB, transferring is not possible for all applications. If the developer has set a flag android:installLocation with value internalOnly in the app manifest, the system will reject the transfer command. In this case, the only option is to use the card only for media files or obtain root access, which will void the device's warranty.
Typical problems and ways to solve them
When using a smartphone with active use of an external memory card, users may encounter a number of specific problems. One of the most common is a card reading error message or applications suddenly disappearing. This is often due to the fact that the memory card is slower than the system expects, or has poor contact in the slot.
If applications start to crash or slow down, check the speed of the card using special utilities, for example A1 SD Bench. Low Random Read rates are the main cause of problems with running apps. In this case, it is recommended to replace the drive with a more productive standard model A1 or A2, which are optimized for working with applications.
It is also possible that after rebooting the phone, application icons become gray or inactive. This happens if the system did not have time to mount the memory card before the interface was fully loaded. Try removing and reinserting the card with the phone turned off, making sure that it is inserted until it clicks. If the problem persists, the card's file system may be damaged and requires reformatting.
What to do if you get the error "SD card is damaged"?
Try to format the card on your computer to the exFAT or FAT32 file system, and then insert it back into the phone to be initialized by the Android system.
Remember that constantly writing and rewriting data to the memory card shortens its service life. Flash memory has a limited resource of rewrite cycles. Regularly make backup copies of important data stored on external media to avoid their loss in the event of a sudden card failure.
Is it possible to transfer system applications (Settings, Phone, Messages) to a memory card?
No, transferring system applications built into the firmware MIUI, is impossible using standard means and via ADB without obtaining root access. Attempts to forcefully move such components can lead to an endless reboot of the phone (bootloop) and the need to reflash the device.
Why, after transferring an application, does it take up space both in the internal memory and on the card?
When transferred to the card, only the main application code (APK) is moved, while user data, cache and some libraries remain in the internal memory to ensure performance. This is normal behavior of the Android system, allowing you to balance between speed and saving space.
Is it safe to format the card as internal storage on Redmi 9A?
The procedure is safe for the phone itself, but you will lose all the data on the card. The main risk is that the card is tied to a specific device. If your phone breaks, you won’t be able to simply insert the card into another phone and read the data - it will be encrypted with your key. Redmi 9A.
How to return a memory card to normal operation after formatting it for internal memory?
To do this, you need to go to the storage settings, select the card and click “Format as portable storage.” The system will warn you that all data will be deleted. After this, the card will become available for reading on other devices, but all transferred applications will have to be reinstalled again.