How to turn a SD- card into internal memory on Xiaomi Redmi 9A: a complete guide with nuances

Owners of Xiaomi Redmi 9A often face a lack of internal memory — especially if you actively install applications, shoot videos or store music. Officially, the smartphone supports memory expansion to 512 GB via microSD, but by default the card is only used for file storage. Fortunately, the MIUI has a hidden feature that allows you to combine the SD- card with internal memory, turning it into a full storage for applications and system data.

However, the process has pitfalls: not all maps fit, data will be deleted after formatting, and some applications may work slower. This article is a step-by-step instruction with illustrations, a speed comparison of A1 vs A2 cards, a compatibility table and solutions to typical errors (for example, "SD- card is damaged" or "Cannot transfer data").

Before you start, check:

• 🔹 Version MIUI: The function runs on MIUI 12 and later (on Redmi 9A out of the box usually costs MIUI 12.0.3 or 12.5). Check in Settings → About Phone → Version MIUI.
• 🔹 Type SD- cards: only microSDXC (from 64 GB) with speed class A1/A2 or UHS-I (U1/U3). Class C10 cards are not going to work!
• 🔹 Free space: The map must have at least 10% free space after formatting.

1 Which SD- cards are suitable for memory expansion on Redmi 9A

Not all microSDs are equally useful, and to combine with internal memory, the card must meet three criteria:

1. Capacity: from 64 GB (maximum - 512 GB, but the Redmi 9A officially supports up to 256 GB).
2. Speed class: A1 or A2 (application optimized) cards labeled C10 or U1 without A1 will not work!
3. Manufacturer: Preference the brands SanDisk, Samsung EVO Plus or Kingston Canvas Go! – they are less likely to be forged.

🔎 How do you check the class of the card? On the case, look for a logo with the letter A and the number 1 or 2 inside:

• 📱 A1 is the minimum threshold for applications (read/write speed ~10 MB/s).
• ⚡ A2 is the optimal option (velocity ~4000 IOPS for random operations).

⚠️ Warning: Cards without A1/A2 class can cause app freezes or a "SD- card is too slow" error when trying to combine. Check the labeling on the package or through the A1 SD Bench app (available from the Play Market) before buying.

2 Preparation of SD- cards before combining with memory

Before you make a card internal memory, it must be formatted in FAT32 or exFAT (but not NTFS!). Redmi 9A will automatically prompt you to do this, but it is better to prepare in advance:

Step 1. Save the data

Formatting will remove all files from the map! Transfer photos, music and documents to your computer or to the cloud (e.g. Google Drive or Mi Cloud).

Step 2. Check the map for errors

Connect the SD- card to your PC and start checking:

• 🖥️ Windows: Open This Computer → PCM by Map → Properties → Service → Check.
• 🐧 Linux/macOS: Use the command sudo fsck /dev/sdX1 (replace sdX1 with your drive).

Step 3: Formatting (if necessary)

If the card has been used on other devices, format it in FAT32 (for cards up to 64 GB) or exFAT (for 128 GB or more). In Windows, this is done via Format in the context menu of the disk. On Mac, use Disk Utility.

3. Step-by-step instruction: how to do SD-memory-card

Now, to the main thing, follow the instructions carefully, because any missed step can lead to errors.

Step 1. Insert the SD- card into your smartphone

Make sure the card is inserted to the point of the slot (on the Redmi 9A it is under the cover next to the SIM- cards). After inserting, a notification will appear "New SD- card discovered".

Step 2. Open the storage settings

Go to:

Settings → Memory → SD- Card] → Triplet (⋮) → Storage settings

Step 3. Select "Inner Memory"

Click Format as internal. The system will warn you that:

• 🔄 All data on the map will be deleted.
• 📱 The card will not be used on other devices without re-formatting.
• 🔒 Some applications may be slower.

Confirm the action by pressing Erase and format.

Step 4: Data Transfer (optional)

After formatting, the system will prompt you to Transfer data (photos, videos, some applications) to the SD- card, a process that can take anywhere from 10 minutes to an hour depending on the file size.

⚠️ Warning: If you interrupt the data transfer, some files may become corrupted. Wait until the process is complete (the screen will show "Transfer Completed").

Step 5: Verification of the result

Once completed, open Settings → Memory. Now the SD- card should be displayed as part of the internal storage (e.g., "Internal Memory: 64 GB (SD- card)").

💡

Once combined, the SD- card cannot be removed without first “disabling” the settings.

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

Even after successful formatting, not all applications will automatically move to the map. Here's how to manually transfer them:

Method 1. Through application settings

1. Open Settings → Applications → Application Management.
2. Select the app you want (such as WhatsApp or Google Maps).
3. Press Warehouse. → Change. → choose SD-map.

⚠️ Not all applications support portability. System utilities (like Settings or Phone) remain in internal memory.

Method 2. via ADB (for power users)

If the Change button is inactive, you can force the application to move through Android Debug Bridge (ADB):

adb shell pm move-package com.example.app /sdcard

Replace com.example.app with the batch name of the application (you can find it through the App Inspector in the Play Market).

Method 3: Automatic portability of new applications

To ensure that all new applications are installed on the SD- card by default:

1. Open the Settings. → Memory. → SD-map.
2. Enable the option to use as a default storage.

💡

If the application slows down after the transfer, try clearing its cache (Settings → Applications → [Select] → Memory → Clear the cache).

5. Typical errors and their solutions

When combining SD- cards with internal memory, Redmi 9A users often face the following problems:

⚠️ Warning: If the smartphone starts to slow down after the combination, check the speed of the SD- card through the application A1 SD Bench. If the read speed is below 10 MB / s, the card is better used only for storing files, not for applications.

A critical nuance for the Redmi 9A: After upgrading the MIUI to the 13+ version, some users report that the combined SD- card is no longer recognized, in which case only a full reset will help (but the data on the map will be saved!).

6 How to cancel the merger and return the SD- card to its original state

If you decide to split the memory back or the card starts to glitches, follow the following steps:

Step 1 Disable the SD- card as internal memory

Go to:

Settings → Memory → SD- Card → Triple (⋮) → Storage settings → Format as portable

⚠️ All data on the map will be deleted!

Step 2: Transfer the data back to internal memory

Before formatting, copy important files from the SD- card to your phone or PC.

1. Connect Redmi 9A to your computer via USB.
2. Enable File Transfer (MTP) mode.
3. Copy data from the SD- folder to the hard drive.

Step 3: Formatting

Once the card is disabled as internal memory, it can be formatted in FAT32/exFAT and used on other devices.

7. Alternative ways to expand memory on Redmi 9A

If the SD- card combination is not suitable (for example, due to a slow card), consider other options:

1. Use of the card as a portable storage facility

Just insert the SD- card and select Use as a portable device in the settings. Minus: applications are installed only in internal memory, but files (photos, videos) can be stored on the card.

2. Transfer data to the cloud

Services like Google Photos or Mi Cloud allow you to automatically upload photos and videos, freeing up space on your phone. On Redmi 9A, this is configured in:

Settings → Accounts → Mi Cloud → Synchronization

3. Optimization of internal memory

Delete unnecessary files through Settings → Memory → Clean up or use apps like Files by Google to find duplicates and large files.

4. Root access and Link2SD

For advanced users, rooting and using Link2SD allows applications to be transferred to the SD- card without formatting, however, this voids the warranty and can lead to unstable system operation.

FAQ: Frequent questions about SD- cards on Redmi 9A