Formatting SD-Maps as internal memory for Xiaomi: a complete guide

Xiaomi smartphones with limited internal storage often face a shortage of space for applications and files, and one solution is to use a microSD card as an internal drive, allowing you to expand the available space without buying a new device, but this process has its own peculiarities, from choosing the right memory card to the technical nuances of formatting in MIUI.

In this article you will find not only step-by-step instructions, but also an analysis of hidden limitations. MIUI When working with adoptable storage (as the technology of combining memory in Android is called), as well as tips for optimizing performance after transferring data, POCO Xiaomi flagships, where the implementation of the function may differ.

What is formatting? SD-maps as internal memory?

The adoptable storage technology introduced in Android 6.0 Marshmallow allows you to use an external memory card as part of the main storage. SD-The card works as a removable disk when formatted in Internal Storage:

• 📱 The card is encrypted and linked to a specific device – it can not be read on another smartphone without formatting.
• 🔄 Applications and their data are automatically transferred to SD (if selected in the settings).
• ⚠️ Performance depends on the class of the card: UHS-I U3 or A2 smooth-working.

It is important to understand that MIUI (Xiaomi firmware) imposes additional limitations, such as some models hidden in the engineering menu, and others completely blocked by the manufacturer, due to Xiaomi’s policy to optimize memory and prevent system slowdowns.

Requirements for SD-card

Not every microSD is suitable for internal storage.

• 📏 Volume: from 16 GB (recommended 32 GB and above for comfortable work).
• 🚀 Speed class: Class 10 or higher, perfect — UHS-I U3/A2 (record 4K-Video and fast application work).
• 🔒 Type of file system: after formatting, it will be ext4 or f2fs (noncompatible Windows/macOS without additional).

Manufacturers whose cards show better compatibility with Xiaomi:

Warning: Class A1 or lower cards can cause lags when running applications with SD. In the tests on the Redmi Note 10 Pro, the difference in read/write speed between the A1 and A2 was up to 40%.

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Before buying, check the card for authenticity with H2testw (Windows) or F3 (Linux/macOS).

Step-by-step instructions: how to format SD-map

The process differs depending on the MIUI version and the smartphone model, and below is the universal algorithm for most Xiaomi Android 9-13 devices:

1. Insert the card into the slot (some models require a reboot to detect).
2. Go to Settings → Memory (or Storage).
3. Tap by name. SD-map → Three points (⋮) → Storage settings.
4. Select Internal Memory (if no option, see If No Formatting Option).
5. Confirm action: the system will warn you about erasing all data and linking the card to the device.
6. Wait until it is completed (it can take up to 10 minutes) and after the reboot, the card will appear as part of the internal memory.

Make a backup of data with SD

Charge your phone at least 50%

Make sure the card is formatted in FAT32/exFAT (if not, format it on PC)

Close all applications that work with memory-->

Important! Some devices (e.g. POCO X3 Pro) require manually transfer applications after formatting:

Settings → Appendices → Select Appendix → Storage → Modify → SD- Map

If there is no option "Internal Memory" in the settings

On some Xiaomi models (especially those with MIUI 12+), the feature is hidden.

Method 1: ADB (for advanced users)

You will need a PC with ADB-tools installed and USB debugging enabled on the phone.

adb shell sm list-disks


adb shell sm partition disk:XX,XX private

Where XX,XX — identifier SD-maps (you can find it on the first command).

Method 2: Engineering menu (for older versions of MIUI)

Enter the phone code in the appendix:

##4636##

Go to Storage → SD Card → Format as Internal. Careful: not all items on the engineering menu are safe to change!

⚠️ Attention: use ADB Or engineering menus can cause system failures. 12/13 These methods are often blocked by the manufacturer.

Transfer of applications to SD-map

Even after successful formatting, not all applications can be migrated.

• 🚫 System applications (MIUI Launcher, Security, etc.) cannot be ported.
• 🎮 High-demand games (such as Genshin Impact) may not run from the SD because of slow reading speed.
• 🔒 Some apps (such as WhatsApp) block the transfer for security reasons.

How to migrate supported applications:

1. Open Settings → Applications → Application Management.
2. Select the application → Warehouse.
3. Click Change and specify SD-map.

Tip: to speed up the work of transferred applications, use the Optimization function SD-card MIUI (available in Settings → Memory. → Three points (⋮)). It caches frequently used data in the internal memory.

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Moving applications to SD can increase their startup time by 20-50% even on A2 cards. Critical applications (messaging, banking) are better left in the internal memory.

Problems and solutions after formatting

Frequent errors and ways to eliminate them:

If after formatting the phone began to slow down:

• 📉 Turn off automatic transfer of new applications to SD (Settings → Memory. → Autotransfer).
• 🧹 Clear the cache of system applications (Settings) → Annexes → Three points (⋮) → Show system-based → Clear the cache).
• 🔄 Restart the device in Safe Mode (hold the power button) → "Restart Safe Mode to check the impact of third-party applications.

⚠️ Attention: on devices with MIUI 14 and later, the function of adoptable storage can be completely disabled due to optimization of the work with the user. UFS 3.1 In this case, the only way out is root rights and modification of system files, which deprives the guarantee.

Alternatives: What to do if formatting is not possible

If your Xiaomi model doesn’t support adoptable storage, consider alternatives:

• 🔄 Link2SD (requires root: creates symbolic links to transfer some of the application data to SD formatless.
• 📁 FolderMount (root): mounts application folders (such as game cache) to SD-map.
• ☁️ Cloud storage: Mi Cloud, Google Drive or Yandex Disk for automatic synchronization of photos and documents.
• 🔌 OTG-drives: connecting the flash drive through the adapter USB-C/OTG (It works on all models without restrictions).

For models with MicroSD+SIM2 support (e.g. Redmi Note 11):

Use a hybrid slot – insert the card instead of the second SIM. Note that in this case you will lose the Dual-SIM capability, but you will get stable SD operation as a memory extension.

FAQ: Answers to Frequent Questions