Owners of budget smartphones, such as the popular Xiaomi Redmi 4A, often face a lack of free space for installing modern applications. Standard 16 or 32 gigabytes of internal memory are catastrophically scarce today, especially given that the system and preinstalled services occupy a significant part of the space. Fortunately, the Android architecture allows you to use an external drive not only as a photo storage, but also fully expand the system partition.
The procedure for combining a flash card with internal memory is called Adoptable Storage, a feature that was introduced in Android 6.0, but many manufacturers, including Xiaomi in the MIUI shell, often hide it from users or restrict functionality. As a result, after installing a microSD card in the slot, the phone suggests using it only to transfer media, leaving applications locked in internal storage.
To solve this problem, you'll need to do a number of technical things that go beyond the standard settings menu, and you'll need to activate the hidden capabilities of the system through USB debugging and a computer. It's important to understand that once you format the card as internal memory, it will become unreadable for other devices without re-formatting. Let's take a step-by-step approach for your device.
Preparation of equipment and software
Before you start modifying the file system, you need to make sure that all the required components are available. The quality of the memory card used directly affects the speed of the Redmi 4A smartphone. Cheap drives with low write speed can lead to noticeable delays in the interface and long start programs.
You will need a computer running Windows, macOS or Linux, as well as a serviceable one. USB-You need to install drivers on your smartphone. ADB, If they're not automatically embedded in the system, it's also critical to back up all the data, because the formatting process will destroy all the information on the map.
- 📱 Smartphone Xiaomi Redmi 4A charged battery (minimum 50%)
- 💾 MicroSD card with a capacity of 16 GB (speed class is recommended) UHS-I higher)
- 💻 Computer with drivers installed ADB and Fastboot
- 🔌 Original or qualitative USB-data-line
⚠️ Note: You perform all actions to change system partitions at your own risk.The author is not responsible for possible data loss or unstable operation of the device.
Make sure that your card doesn't have important files, or copy them to your computer in advance. The process of combining involves completely erasing the partition structure of the drive. If you use a new card, this step can be skipped, but checking its health will not hurt.
Configure the developer mode and debug over USB
To interact with deep Android settings, you need to activate a hidden developer menu. In standard mode, these options are not available to the average user. 4A steerable MIUI The activation process has its own features related to the Mi Account account.
First, go to Settings → About Phone and find the MIUI Version line, which you need to quickly click on 7-10 times in a row until you notice that you have become a developer. However, unlike pure Android, Xiaomi requires additional activation.
Go to Settings. → Advanced settings → For developers, you need to find the Debugging item here. USB And you can activate it. The system can issue a security alert, OK, but you can also have a security alert "USB-Debugging (security settings) and allowing applications to be installed from unknown sources.
☑️ Checklist of smartphone preparation
When you connect your phone to your computer in debugging mode, you'll see a request on your smartphone screen for debugging permission from that computer, and you'll be sure to tick "Always Allow" and click "OK." Without that confirmation, the computer won't be able to send the necessary commands.
Installation and verification of ADB connection
Now you need to establish a connection between your computer and your smartphone, using the Android Debug Bridge (ADB) toolkit, download the current version of Platform Tools from Google's official website or use a proven driver installer.
After unpacking the archive with tools, open the command line (Terminal on Mac/Linux or CMD/PowerShell on Windows) in the folder with ADB files. Connect the phone with a cable to the PC. Enter the connection check command:
adb devicesIf a device with a serial number and a device status appears on the list, the connection is correct. If it's unauthorized, look at the phone screen and confirm access. If it doesn't show at all, check the cable or install the drivers manually.
What to do if your computer can’t see your phone?
Once you've successfully connected, you can go to the main command, which will turn your card into part of the system partition, which will change the file system of the drive to a format that only your particular phone can understand.
Formatting a map through the command line
The most important step is to execute the formatting command, and type the following code in the command line that initiates the creation of an internal memory partition on an external medium:
adb shell sm partition public:0 private:100This command tells the system (sm - storage manager) to share memory. public:0 means that 0% of the card will remain available as a normal storage (removable disk) and private:100 It gives away 100% of the volume to internal memory, and it takes a few minutes to process, during which time the phone may not be available.
Once you have completed the command, the phone can restart or give a notification to set up a new drive. Follow the instructions on the screen: select "Use as internal storage." The system may suggest moving data from the old internal drive to the new one -- if there is space available, you can agree.
| Parameter of the team | Meaning | Description of action |
|---|---|---|
| sm partition | Team team. | Starting a disk partition manager |
| public:0 | 0% | The share of the card remaining a removable carrier |
| private:100 | 100% | The share of the card that becomes the internal memory |
| mixed:50 | 50/50 | Alternative splitting (half by half) |
If the command is successful, in the Settings → Memory menu, you will see that the total amount of internal memory has increased. Now the applications will be installed on the map by default, unless the developer has prohibited it.
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If the sm partition command gives an error, try formatting the card as a removable medium first through the phone's menu, and then repeating the ADB command.
Application portability and work optimization
Once memory is combined, the system doesn't always automatically transfer all applications. You need to manually control this process to free up space on the embedded chip. Go to Settings → Applications → All applications.
Select a heavy application, such as a social network or a game. If the developer has authorized the transfer, the Move button will be active. Press it to transfer data to the map. Note that the system applications cannot be moved.
For some applications that do not have a port button, you can use the command ADB It's a forced transfer, but it requires root rights or specific manipulation of each packet separately. 4A Standard transfer is sufficient to install new programs.
- 🚀 Move games with large cache first
- 📸 Messengers (Telegram, WhatsApp) are better left on internal memory for speed
- 🗑️ Remove unused applications before transferring
⚠️ Note: Applications ported to a memory card may be slower than those with internal memory, especially if the old standard card is used.
Possible problems and solutions
You can experience situations when your phone stops seeing the card or apps start crashing, often due to file system errors or poor contact. First of all, try restarting the device.
If the problem persists, the memory card may be damaged or has a slow write rate. Try checking it on your computer using the h2testw utility. It will show the real volume and the presence of errors. It is also worth checking whether the smartphone overheats, since the Redmi 4A is sensitive to temperatures.
In some cases, re-formatting through ADB helps. First, you need to delete the section:
adb shell sm destroyWhere <ID_disk> — This is your card ID, which you can find by adb shell sm list-disks. After deleting the partition, format the card again as normal, and then repeat the process of combining.
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Stability of the combined memory depends on the quality of the microSD card: use branded drives (Samsung, SanDisk, Kingston) of the UHS-I class.
Return to baseline
If you decide to sell your phone or return it to the same way, you need to format the card back to standard mode. You can't just pull it out, the phone will swear that there's no internal memory. Go to Settings → Memory.
Click on your card name and select Format or Undo the unification option, the system will warn you that all data will be deleted, confirm the action, and then the card will become a normal removable media again.
After formatting, it is recommended to restart the phone, all applications that have been transferred to the map will disappear from the installed list, and they will have to be downloaded again, and personal files that remain in internal memory will be saved.