Combining the memory of the phone and SD-Xiaomi Redmi 9 maps: a complete guide with nuances

Owners of Xiaomi Redmi 9 often face a shortage of internal memory, especially if the model is purchased with a basic configuration (32 or 64 GB). Even after cleaning the cache and removing unnecessary files, the system can show a warning about overflowing storage. The solution is to combine the memory of the phone and microSD cards into a single section. But there are pitfalls: not all memory cards are suitable, and improper actions can lead to data loss or slowdown of the smartphone.

In this article, we will discuss the 3 official ways to combine memory on Redmi 9 (relevant to MIUI 12-14), their pros and cons, as well as alternative options for users who have not worked with the standard method. We will focus on compatibility of memory cards, formatting settings and how to avoid typical errors. If you have already tried to combine memory and received the message "This card is not supported" - here you will find a solution.

⚠️ Important: Memory integration irreversibly deletes all data from SD-Before starting the procedure, copy important files to a computer or cloud, and note that once combined, the card will not be retrieved, it will become part of the system.

1. Which memory cards are suitable for combining with Redmi 9

Not every microSD is suitable for expanding internal memory. Xiaomi Redmi 9 supports microSDXC cards (up to 512 GB) with a speed class UHS-I (U1/U3) or A1/A2. However, a few more conditions are required to successfully combine:

• 🔹 Minimum volume: 16 GB (32 GB and higher recommended) Cards less than 16 GB will not be offered to combine.
• 🔹 File system: exFAT or FAT32 (But when you combine it, the phone formats it into ext4 or f2fs).
• 🔹 Manufacturer: Preference give brands SanDisk, Samsung EVO, Kingston Canvas – Cheap no-name cards often fail compatibility tests.
• 🔹 Write speed: No less than 10 MB/s (class 10). For smooth operation of applications from the card, it is better to choose a model with a marking A2 (For example, SanDisk Ultra A2).

If you have already inserted a card, but the phone does not see it or does not offer to combine it, check:

1. Does the card support UHS-I mode (specified on the package)
2. Is the card damaged (try formatting it on PC via SD Formatter).
3. Is the card used as a portable storage device in another device (e.g., a camera)?

Step-by-step: how to combine memory through MIUI settings

This is the official method that works on Redmi 9 with MIUI 12, 13 and 14.

• 📱 The phone is charged at least 50% (the process can take 10-30 minutes).
• 📁 There is no important data on the map (it will be erased!).
• 🔌 The card is inserted into the microSD slot, not through the adapter to the port. USB-C.

Follow the algorithm further:

1. Open the Settings. → Memory. At the top of the screen, you'll see two bars: internal memory and SD-Click on the line with the name of your card (for example, SD-map: 128GB).
2. Select Storage Settings → Format as internal memory. If this item is missing, your card does not fit (see Section 1).
3. Confirm formatting. The system will warn you that all data will be deleted. Press erase and format.
4. Wait until the process is complete. The phone will reboot, and the card will become part of the internal memory. Applications can now be transferred to it through Settings → Applications → [Select App] → Storage → Change.

Make sure the card is compatible (class U1/A1, ≥16 GB)

Copy all data from SD to PC/cloud

Charge your phone at least 50%

Insert the card into the microSD slot (not via the adapter)

Check the free space on internal memory (≥ 1 GB)

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⚠️ Warning: Once combined, the card cannot be retrieved, causing the applications installed on it to malfunction. If you need to temporarily use the card on another device, first divide the memory through Settings. → Memory. → [Name of the map] → Data transfer and resetting.

3. Why the phone doesn't offer to merge memory: common mistakes

If the “Format as internal memory” option is not available in the settings, the reasons may be as follows:

If none of these methods worked, try an alternative method. ADB (Also make sure that your Redmi 9 has the latest version installed. MIUI — In the old firmware could be bugs with support SD-map.

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Before buying a memory card, check it for authenticity with H2testw (Windows) or F3 (Linux/macOS). Many cheap cards have an understated real capacity.

4. How to transfer applications to SD-post-community

Once the memory is successfully combined, the applications will be installed on the internal memory by default. SD-map:

1. Go to Settings → Applications → Application Management.
2. Select the app you want (such as WhatsApp or Google Maps).
3. Press Warehouse. → Change.
4. Choose. SD-map and confirm the transfer.

⚠️ Note: Not all applications support porting to a memory card, such as system utilities (Settings, Phone) and some games (e.g, PUBG Mobile may not offer this option:

• 📲 Application portability does not free up internal memory completely – some data (cache, settings) remains mostly storage.
• ⚡ Annexes to SD-The card may work slower, especially if the class card is U1 (not A2).
• 🔄 After the map is extracted, the transferred applications will stop working.

To speed up the work of applications with SD-maps recommended:

• 🔹 Use cards with markings A2 (They are optimized for randomly writing small files).
• 🔹 Do not transfer messengers (Telegram, Viber) to the map - they actively work with the cache and can slow down.
• 🔹 Regularly clear the cache of transferred applications through Settings → Memory. → Cleanup.

5. Alternative method: Memory integration via ADB (for power users)

If the standard method didn’t work, you can try forcibly formatting the card as internal memory via Android Debug Bridge (ADB), which requires connecting the phone to a computer and basic command line knowledge.

You'll need:

• 🖥️ Computer with Windows/Linux/macOS.
• 🔌 Cable USB-C (preferably original).
• 📦 Installed Xiaomi drivers and package ADB Tools.

Instructions:

1. Turn on the phone Developer Mode: Settings → About Phone → MIUI version (click 7 times).
2. Activate USB Debugging in Settings → Additional → For developers.
3. Connect your phone to your PC and start the command prompt (cmd in Windows or Terminal in macOS/Linux).
4. Enter the commands in turn: adb devices (should appear serial number of your phone) adb shell sm list-disks (remember disk ID, for example, disk:179.64) adb shell sm partition disk:179.64 private (replace 179.64 with your ID)
5. Reboot the phone. Once turned on, the card will be formatted as internal memory.

⚠️ Attention: Misuse of the right ADB If you are not sure about your actions, you should contact the service center or use the standard method of combining.

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The ADB method is only suitable for cards that MIUI does not want to format automatically, and does not increase the chances of success if the card is initially incompatible (for example, U0 class or <16 GB volume).

6 How to divide memory back: return SD-map

If you decide to retrieve the card or it starts to work unstable, you can return it to portable storage mode.

1. Go to Settings. → Memory.
2. Click on the line with your name SD-cards (e.g., internal memory: 128GB).
3. Select Data Transfer and Reset → Format as a portable device.
4. Confirm the action. The phone will reboot, and then the card can be retrieved.

⚠️ Important: When you split the memory, all data from the card will be deleted:

• 📱 Annexes to the Convention SD-map, stop working.
• 🔄 After separation, the card can be used in other devices (camera, other phone).
• ⚡ If the phone after the memory split began to slow down, reboot.

If the option “Format as a portable device” is missing, try:

1. Connect your phone to your PC and format the card via Disk Utility (macOS) or Disk Disk Management (Windows).
2. Use it. ADB-Command: Adb shell sm erase force disk:179,64 (replace 179.64 with your drive ID).

7. Alternatives to memory unification: what to do if nothing helps

If your card is not suitable for integration or you do not want to risk the stability of the system, consider alternative ways to free up memory:

• 📁 Transfer media files: Manually move photos, videos and music to SD-file-card → Categories → Images/Video → Select → Move it.
• ☁️ Cloud Storage: Set up an automatic photo upload in Google Photos or Mi Cloud (in Settings) → Accounts. → Mi Cloud → Synchronization).
• 🗑️ Cache Clearing: Clean the app cache regularly through Settings → Memory. → Cleaning or using CCleaner.
• 🔄 Factory reset: The last method if the phone is heavily clogged. pre-backup through Settings → The phone. → Backup.
• 🛒 Replacement of memory card: If the current card is not supported, buy a model marked A2 (For example, SanDisk Extreme A2 128GB).

For users who often install heavy games (such as Genshin Impact or Call of Duty Mobile), the best solution is to buy a Redmi 9 with a large amount of internal memory (128 GB) or switch to a model with support for microSDXC (such as the Redmi Note 10 Pro).

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If you often shoot videos in 4K, Configure the camera to save files immediately on SD-Map: Camera settings → Preservation site → SD-This will save internal memory.

FAQ: Frequent questions about memory pooling on Redmi 9