How to combine memory on Xiaomi Redmi 9: all the ways and nuances

Xiaomi Redmi 9 is a popular smartphone with the ability to expand memory via microSD, but many users face a lack of space even after installing a card. Combining internal memory with external memory (Adoptable Storage) allows you to use them as a whole, but this method has pitfalls. In this article, we will discuss all the working ways of combining, their pros and cons, as well as alternative solutions for optimizing space.

Important: the procedure depends on the MIUI version and the type of memory card. Not all Redmi 9 supports full integration - in some cases only application portability is available. We tested the methods on MIUI 12.5-14 and found key differences. If you use Redmi 9A/9C/9T, note that these models may have different algorithms (for this, see a separate section).

What is a Memory Unit and Why You Need It

Adoptable Storage is an Android feature that allows you to format a microSD as part of your internal storage, and then it sees the card as an extra partition where you can install applications and store data, and the main advantage is saving space in your main memory, but there's a downside:

• 🔄 The card becomes “tied” to the device – it cannot be retrieved without losing data.
• ⚡ The speed of work depends on the class. SD (recommended UHS-I Class 10 or higher).
• 📱 Not all apps work properly with external memory (especially cache games).
• 🔧 After combining, the card cannot be used on other devices without formatting.

On Redmi 9, the function is implemented via MIUI, but with limitations. For example, you can not combine memory if the card is already used as a portable storage, and it is worth considering that after combining some functions (for example, OTG) can work unstable.

Preparation for the Association: Requirements and Checks

Before starting the procedure, follow the mandatory steps:

1. Check the memory card: it should be at least 16 GB (optimally 32-128 GB) and UHS-I/U3 or Class 10. Cheap cards can slow down the system.
2. Back up: all data from the map will be deleted. Use Google Photos for photos or Mi Cloud for contacts.
3. Battery charge: At least 50% to avoid failures.
4. Update MIUI: Older versions (below MIUI 12) may not have unification options.

To check the card’s compatibility, insert it into the slot and go to Settings → Storage → SD Card. If the system offers the option “Configure as internal memory”, then the card is suitable. If not, try formatting it into FAT32 or exFAT via a PC (but this does not guarantee success).

Save data with SD-PC/cloud maps

Check the class and size of the card (minimum Class 10, 16 GB)

Charge your phone to 50% or higher

Update MIUI to the latest version

Make sure the card is not damaged (check on another device)-->

⚠️ If you are using Redmi 9S MIUI Global, after memory is combined, problems with updates over the air may arise (OTA). In this case, it is recommended to temporarily disable the card before updating.

Method 1: Combining via MIUI settings (official method)

It's the easiest and safest way, but it's not available on all firmware versions. MIUI 12.5–14:

1. Insert microSD into the slot (up to 512GB cards are supported).
2. Open the Settings → Storage → SD card.
3. Slip on the three dots in the top right corner and select "Storage settings."
4. Select “Format as internal” (or “Configure as internal memory”).
5. Confirm the action. The system will warn you that all data will be erased.
6. Wait for the formatting to be completed (it can take up to 10 minutes).
7. After the reboot, go to Settings → Applications → Installed and transfer the necessary programs to the map.

If the option "Format as internal" is missing, then:

• 📱 Your version. MIUI does not support the function (relevant to the MIUI 11 and below).
• 💾 Memory card damaged or incompatible.
• 🔧 The device already uses the card as a portable storage (you need to format it in the form of a portable storage device). FAT32 PC).

Method 2: Manually combine via ADB (for power users)

If you don’t have a combination option, you can use Android Debug Bridge (ADB), which works on most Android 9-12 versions, but requires a PC connection. On Redmi 9 with MIUI 13+, this method may not work due to Xiaomi’s restrictions on modifying the storage partition.

Step-by-step:

1. Download and install ADB Tools on your PC (e.g. Google’s Platform Tools).
2. Activate Developer Mode on Redmi 9: Go to Settings → About Phone → MIUI version and tap 7 times.
3. Enable USB debugging in Settings → Additional → For developers.
4. Connect the phone to the PC and confirm the debugging permission.
5. Open the Command Prompt (CMD) in the ADB folder and type:

adb shell


sm list-disks

You will see a card ID (e.g., disk:179,32) and copy it and follow the command:

sm partition disk:179,32 private

The card will then be formatted as internal memory, and if you have entered the wrong ID, you may lose the data on the main drive!

⚠️ Note: On some versions MIUI after-unification ADB You may have errors with the mounting of memory when you reboot, and only a complete reset will help.

Method 3: Transfer applications to SD-map (alternative to association)

If memory integration is not possible or desirable, you can manually transfer some applications to the map, which is less effective but safer:

1. Open Settings → Applications → Application Management.
2. Select the app you want to migrate (not all programs support this option).
3. Slip "Storage" → "Change" → "SD card".
4. Confirm the transfer. Some data (cache, updates) may remain in internal memory.

Limitations of the method:

• 🎮 The big cash game (Genshin Impact, PUBG) They may not be able to move or work slower.
• 📱 System applications (Google Play, Mi Services) cannot be moved.
• 🔄 After updating the application, it can automatically return to internal memory.

To automatically transfer new apps to the card, activate the option in Settings → Storage → SD Card → Settings → Set by default on SD (not available on all versions of MIUI).

💡

If the app is slowing down after transfer, try clearing its cache in the settings. Also check the speed of the memory card - UHS-II or A2 is recommended for games.

Frequent problems and their solutions

Memory integration on Redmi 9 is often accompanied by errors, and let’s look at the typical cases and ways to fix them:

If the card is identified as damaged after the merger, try:

1. Remove and re-insert it.
2. Execute the command in ADB:

adb shell sm repair disk:179,32

(Replace 179.32 with your card ID).

Features for Redmi 9A, 9C and 9T

On the Redmi 9A/9C/9T modifications, the process of combining memory has nuances:

• 📌 Redmi 9A: It does not support Adoptable Storage at the level of MIUI. The only option is to transfer applications manually or use them ADB (But it can cause disruption).
• 📌 Redmi 9C/9T: feature is available, but works unstable on firmware below MIUI 13. Preliminary updates are recommended.
• 📌 All models with eMMC memory (instead of the UFS) Unification can slow down the system due to the difference in reading speed.

For the Redmi 9A, an alternative way to save space is:

1. Use Google Drive (Mi Cloud) to store photos and videos.
2. Remove pre-installed applications via ADB:

adb shell pm uninstall -k --user 0 com.mi.global.bbs

(Replace com.mi.global.bbs with an unnecessary application package)

💡

On Redmi 9A, memory integration is officially unavailable, and the best way to do that is to optimize internal storage and use cloud services.

FAQ: Answers to popular questions