Formatting SD-Xiaomi Redmi 9: 3 Proven Ways

Formatting SD-Xiaomi Redmi 9 cards are a procedure that every smartphone owner will face sooner or later: Whether you want to make room for new files, eliminate read errors or prepare the drive for use as internal memory. However, missteps can lead to data loss or even damage to the map. In this article, we will discuss all available formatting methods, including hidden nuances that are not written about in standard instructions.

The Redmi 9 (M2003J15SC, M2004J19C, etc.) features up to 512 GB of microSD support with internal storage (Adoptable Storage), but before that, the card needs to be formatted correctly, and many users make critical mistakes, such as choosing the wrong file system (FAT32 instead of exFAT for >4 GB files) or ignoring backup before the process.

We tested all the ways in Redmi 9 with MIUI 12/13/14 firmware (including global and Chinese versions) and found the best settings for different scenarios. In this article, you will find not only step-by-step instructions, but also a file system compatibility table, tips for recovering data after random formatting, and answers to frequent questions - for example, why the smartphone does not see the formatted card.

Preparation for formatting: what to do before the start

Before you start formatting, follow the mandatory preparatory steps, which can lead to the loss of important data or malfunction of the smartphone.

First, back up all the data from SD-Even if you plan to format it as internal memory, files will be deleted without the ability to recover through standard means. MIUI. Use it for copying:

• 📁 Conductor MIUI: Go to the Files. → The device → SD-map, select folders and click "Copy» → specify the target folder on internal memory or connected PC.
• 🖥️ Computer: Connect Redmi 9 to USB file transfer (MTP), copy the data to a hard drive.
• ☁️ Cloud services: upload files to Google Drive, Mi Cloud or Yandex Disk (with limited traffic, it will take time).

Second, check your health. SD-If the drive is damaged, the formatting can make the problem worse:

1. Connect the card to the PC through the card reader.
2. Run Command Prompt on behalf of the administrator.
3. Enter the command: chkdsk X: /f (where X is the letter of the disk SD-map).

If the command issues errors such as "Windows has made corrections to the file system", the card needs to be replaced.

⚠️ Attention: If SD-The card was used as an internal memory (Adoptable Storage), it can not be simply removed and formatted on a PC. First, mount it in the settings of Xiaomi (Settings). → Memory. → SD-map → Settings → Format as portable, otherwise you risk losing access to data forever.

2. Method 1: Formatting through MIUI settings

The easiest method is to use the built-in MIUI tools, which are suitable for most users and do not require additional devices.

Instructions:

1. Open the Settings → Memory.
2. Tap the line. SD-card (if not, check if the card is inserted correctly).
3. In the upper right corner, press three dots (⋮) and select Storage Settings.
4. Select Format → Format as internal (for memory expansion) or Format as portable (for normal use).
5. Confirm the action, wait for the completion (it will take 1-5 minutes depending on the size of the card).

Important nuances:

• 🔄 When you choose to Format as an internal card, it will be encrypted and tied to your Xiaomi. Once extracted, it will not be read on other devices without resetting.
• 📉 If the free space on the map is less than expected after formatting, check for hidden files (for example, folders.android_secure for secure application data).

If the formatting option is inactive, the reasons may be as follows:

Method 2: Formatting with Recovery Mode

If MIUI doesn’t allow you to format your card (for example, due to system failures), use Recovery Mode, which is also useful if your smartphone isn’t booting.

Step-by-step:

1. Turn off Redmi 9.
2. Press the Power + Volume buttons up until the Mi logo appears.
3. In the Recovery menu, select the language (use volume buttons for navigation, power button for confirmation).
4. Go to Wipe & Reset → Wipe SD Card.
5. Confirm the action and wait for the completion.
6. Select Reboot → Reboot to System to reboot.

⚠️ Note: In some versions of Recovery (for example, in Chinese firmware) the Wipe item SD The card may not be available. In this case, use ADB-Commands: Adb shell sm partition disk:179,64 private (where 179.64 is the identifier) SD-This requires an unlocked loader.

Advantages of the method:

• ✅ It works even if the main system is damaged.
• ✅ Allows you to bypass restrictions MIUI (For example, if the card is “hung” as an internal memory).

Disadvantages:

• ❌ No file system selection – standard will be used MIUI (FAT32 or ext4 internal memory).
• ❌ Risk of accidental resetting of settings if you select the wrong menu item.

4. Method 3: Computer formatting (Windows/macOS/Linux)

If the standard methods do not work, connect SD-This way you can control the process more, like choosing a file system or doing low-level formatting to repair damaged sectors.

Instructions for Windows:

1. Insert the card into the card reader and connect to the PC.
2. Open this computer, find the disk. SD-cards (e.g. Disc D:).
3. Right-click. → Format.
4. Select the options: File system: FAT32 (for compatibility) or exFAT (for files >4 GB). Cluster size: 32768 (optimum for cards >32 GB). Volume label: any name (for example, XiaomiSD).

Start.

For macOS:

1. Open the Disk Utility (Applications → Utilities)
2. Choose. SD-left-hand-menu.
3. Click Erase, specify: Format: MS-DOS (FAT) or ExFAT. Scheme: GUID Partition Scheme (for cards > 2 TB).

Erase

For Linux (terminal):

sudo fdisk -l # find the SD device (e.g. /dev/sdb)


sudo mkfs.vfat -F32 /dev/sdb1 # for FAT32



or



sudo mkfs.exfat /dev/sdb1 # for exFAT (exfat-utils package required)

⚠️ Attention: On Redmi 9 firmware MIUI 12+ maps formatted on PC in NTFS, They won't be recognized. Just use them. FAT32/exFAT.

If standard formatting doesn’t help (e.g., a card is defined as RAW), complete the cleanup via DiskPart (Windows):

diskpart


list disk




select disk X (where X is the SD- card number)




clean




create partition primary




format fs=fat32 quick




exit

💡

If the smartphone doesn’t see the card after formatting on your PC, reboot the Redmi 9 with the SD inserted. Sometimes MIUI takes time to initialize a new drive.

5. File system selection: FAT32 vs exFAT vs ext4

Compatibility, maximum file size and speed depend on the file system. SD-There are three options available on Redmi 9:

Recommendations:

• 📱 For portable use (photos, music, documents) choose exFAT if the card is used. >32GB.
• 🔧 For internal memory (adoptable storage) MIUI automatically ext4 — No need to change it.
• ⚠️ NTFS Redmi 9 is not supported at the kernel level (although some file managers may see it").

Critical information: If you format the card in ext4 on a PC and then paste it into Redmi 9 as a portable card, the smartphone will suggest formatting it again. Data will be lost!

6. Solving problems after formatting

Even after successful formatting, errors can occur, and let's look at typical scenarios and how to fix them.

Problem 1: The smartphone does not see the formatted SD-map.

• 🔌 Reboot Redmi 9 with an inserted map.
• 🛠️ Check the card on PC: if it is not determined, try another card reader.
• 📱 In the settings MIUI Go to Memory. → SD-map → Settings → Mount.

Problem 2: The map is defined but not the files.

• 🔒 Check if the Write Protection is not on (physical switch on the adapter).
• 📂 Re-format the map by selecting exFAT instead of FAT32.
• 🛡️ If the card was used as internal memory, reset it through Settings. → Memory. → SD-map → Formatting as a portable.

Problem 3: After formatting as internal memory, less space is available than expected.

• 📊 Part of the space is reserved for Android service files (for example, for the use of Android files). /android/obb/).
• 🔍 Check hidden folders through a file manager with root permissions (for example, FX File Explorer).
• 🔄 If the difference is critical (for example, a 128 GB card shows 60 GB), format it as portable and repeat the procedure.

💡

If SD-The card after formatting is unstable (for example, files disappear), check it for authenticity using the utility H2testw (Windows or F3 (Linux/macOS). Fake cards often have an understated real capacity.

7. Data recovery after random formatting

If you're formatting. SD-map with important data, do not panic - the chances of recovery are there, but they depend on the type of formatting and actions after it.

What to do immediately:

1. 🛑 Stop using the card – any record of new data reduces the chances of recovery.
2. 💾 Connect the card to the PC via card reader (not via smartphone!).
3. 🔍 Use recovery software: Recuva (Windows, free). PhotoRec (Windows/Linux/macOS, free of charge, working with ext4). DiskDigger (Android, requires root for deep scanning).

Recovery features for Redmi 9:

• 📱 If the card has been formatted as internal memory, standard utilities (like Recuva) won’t see it. Use PhotoRec in Whole disk mode.

⚠️ Note: If you have used the Adoptable Storage feature, the data on SD-The cards are encrypted with a key attached to your Xiaomi. You can't recover them without accessing the original device (even with root).

Prevention for the future:

• 🔄 Regularly copy important data from SD-cloud-card.
• 📌 Use cards in the class no lower A1 (For example, SanDisk Ultra A1) — They are optimized for Android and are less likely to fail.
• 🚫 Avoid cheap no-name cards – they often have poor memory quality and can be damaged when used heavily.

FAQ: Frequent SD Formatting Questions on Redmi 9