How to combine internal memory and SD-Map on Xiaomi Redmi 9: a complete guide with nuances

Xiaomi Redmi 9 is one of the most popular budget smartphones with the ability to expand memory through a microSD card. But what if 64 or 128 GB of internal memory runs out, and the applications stubbornly refuse to install on a removable drive? SD-But this process has its pitfalls, from data loss to malfunctioning of some applications.

In this article, we will discuss a unique method of combining memory for Redmi. 9 base MIUI 12/13/14, It's more stable than standard formatting, like an internal drive, and you'll learn how to prepare a memory card, what you're setting. MIUI It affects the outcome, and what to do if the system doesn't see the unified partition, and why some apps (like WhatsApp or banking) might refuse to work with the combined partition. SD-map, even after successful association.

Why Standard Formatting as Internal Memory Doesn't Always Work

Many Redmi 9 users face a problem: once you select Format as an internal drive in the storage settings, the system either issues an error or the memory card becomes unreadable, and there are three key reasons:

• 🔹 Incompatibility of the file system. MIUI by default, trying to format the card in ext4 or f2fs, MicroSD (especially the microSD class) A1) They often don’t support these formats.
• 🔹 Manufacturer restrictions: Xiaomi blocks full-fledged unification on some firmware due to the risk of data loss when retrieving the card.
• 🔹 Adoptable Storage: Adoptable Storage (built into Android) doesn't work properly on custom shells like the one on the back of the phone. MIUI, unless additional settings are made.

Moreover, even if the merger is successful, some apps (such as Google Play Store or Netflix) may not see or refuse to install extended storage, due to Android’s security policy, which prohibits the transfer of critical data to removable media.

Preparation SD-Cards: Which cards are suitable and which are not

Not every microSD card is suitable for combining with internal memory, but here are the key requirements for Redmi 9:

⚠️ Attention: Class maps A1 They support application installation in theory, but in practice they often cause lags and errors when working with combined memory. If your card is slower than 80 MB / s on record, it is better to use it only for storing media files, not for expanding memory.

Before the merger it is mandatory:

1. Create a backup copy of all data from the card (photos, videos, documents).
2. Check the card for errors through your PC (for example, the chkdsk utility in Windows).
3. Format the card in exFAT via your computer (not your phone!).

💡

If the card has been used in another device (e.g., a camera), complete formatting, not fast formatting, will delete any service files that may interfere with the integration.

Step-by-step: how to combine memory on Redmi 9

There are two ways to combine: through standard MIUI settings and through ADB (power users), and we'll look at both, but we'll start with a more secure option.

Method 1: Through Storage Settings (without ADB)

This method is suitable for most users, but does not work on all versions of MIUI.

1. Insert the microSD card into the Redmi 9 slot (microSDXC support up to 512 GB).
2. Go to Settings. → Memory. → Storage settings → SD-map.
3. Slip on the three dots in the upper right corner and select Storage Settings (or Format as an internal drive).
4. Confirm the formatting. The system will suggest that you move the data, and only accept it if you are sure that the map is stable.
5. After the reboot, check the combined section in Settings → Memory.

⚠️ Warning: If the phone starts to brake after the combination or the apps crash, go back to separate storage:

1. Go to Settings. → Memory. → SD-map.
2. Select Format as Portable (all data will be deleted!).

Method 2: ADB (for experienced users)

If the standard method doesn’t work, you can force Adoptable Storage to be enabled via ADB. This method requires a PC and enabled USB debugging.

Instructions:

1. Activate Developer Mode: Go to Settings → About Phone → MIUI version and tap 7 times.
2. Enable USB debugging in Settings → Additional → For developers.
3. Connect Redmi 9 to your PC, install Mi PC Suite drivers (if Windows doesn’t recognize the device).
4. Open the command line (Win + R → cmd) and type:

adb shell


sm list-disks

You will see a card ID, such as disk:179.64.

sm partition disk:179,64 private

Once rebooted, the card will become part of the internal memory, but beware: this method can lead to unstable operation if the card is slow or damaged.

What applications can be transferred to the combined memory, and which – not

Even after successful integration, not all applications will work correctly with the SD-Here are the key constraints:

• ✅ Can be transferred: Games (e.g. Genshin Impact, PUBG Mobile - but expect longer downloads. - Media players (VLC, MX Social networks (Facebook, Instagram – but the cache will remain in the internal memory).
• ❌ Banking applications (SberBank Online, Tinkoff – blocked for security reasons); Messengers (WhatsApp, Telegram – may not see media files); System utilities (Google Play Market, Mi App Store).

⚠️ Attention: Transfer of applications to SD-map may lead to:

• Increased launch time (especially for games)
• Data saving errors (e.g. Brawl Stars or Clash of Clans)
• Automatic return to internal memory after updating.

To transfer the supported application:

1. Go to Settings → Applications → Application Management.
2. Select the desired application → Warehouse → Change. → SD-map.
3. Confirm the transfer (the process may take a few minutes).

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Transfer of applications to SD-The card does not free up the internal memory completely - some of the data (cache, settings) will still remain in the main storage.

Frequent mistakes and their solutions

When you combine memory on Redmi 9, users face typical problems.

If Redmi 9 starts to overheat or discharge quickly after the merger, it is a sign that the memory card is not coping with the load.

1. Check the temperature with AIDA64.
2. If the CPU is loaded 50%+ in idle, roll back to separate storage.
3. Try another card (e.g. Samsung PRO Endurance for heavy loads).

Alternative ways to expand memory without combining

If the combination is not suitable (for example, due to a slow card or unstable operation), consider alternatives:

• 📁 Transfer media files: Manually move photos, videos and music to SD-map MIUI. This will free up 10 to 30 GB of internal memory.
• ☁️ Cloud Storage: Set up automatic photo uploads in Google Photos or Mi Cloud (up to 5GB free).
• 🔄 Cache Cleanup: Clean the cache regularly through Settings → Memory. → Cleaning (can be released up to 5-10 GB).
• 🎮 Lite versions of applications: Install lightweight versions of social networks (Facebook Lite, Messenger Lite), which take up 2-3 times less space.

For games, there is another life hack: many projects (for example, Call of Duty Mobile or Free Fire) allow you to save resources (textures, sounds) on the Internet. SD-This is the map:

1. Start the game.
2. Go to the graphics settings.
3. Select the option to download resources to SD-card (if available).

How to Get Everything Back: Canceling Memory

If the combined memory is unstable or you decide to sell the Redmi 9, you can return separate memory in two ways:

Method 1: Through the MIUI settings

1. Go to Settings. → Memory. → SD-map.
2. Slip on three points → Storage settings → Format as portable.
3. Confirm the action. All data from the map will be deleted!

Method 2: Recovery (if the phone is not turned on)

If Redmi 9 has stopped downloading after the merger:

1. Press Power + Volume Up to Enter Recovery Mode.
2. Select Wipe & Reset → Wipe All Data (reset to factory settings).
3. After rebooting, insert the card again – it will be defined as portable.

⚠️ Note: If the card has been formatted as an internal ADB, The standard reset may not help:

1. Connect the phone to the PC.
2. Enter the ADB:

adb shell


sm list-disks




sm partition disk:179,64 public

(Replace 179.64 with your current card ID.)

FAQ: Answers to Frequent Questions