How to format a memory card on Xiaomi: all the ways and nuances

Why Xiaomi Memory Card Formatting Needs Attention

MicroSD cards in Xiaomi smartphones are often a source of problems, from slow operation to complete unavailability of files. The reasons are not only the physical wear of the drive, but also in the wrong file system, data fragmentation or conflicts with the MIUI firmware. For example, if you transfer a card from an old phone to a new Redmi Note 12, the system may not recognize it due to outdated FAT32 markup, optimal for files up to 4 GB.

Formatting isn’t just a memory cleanup; it’s a sector re-marking process that determines how a device will write and read data. On Xiaomi with MIUI 14+, it’s important to take into account the nuances: some models (like the POCO F5) automatically offer exFAT for cards over 64GB, while budget devices like the Redmi A2 can be limited to FAT32. A mistake in choosing a file system will result in a loss of speed or inability to write files larger than 4GB.

Preparation of memory card for formatting

Before you start, make sure that the map is not important data, even if you plan to format quickly, there is a risk of losing files due to failures.

• 📁 Backup to the cloud (Mi Cloud, Google Drive) or PC.
• 🔋 Charge your smartphone by at least 50% – interruption of the process due to battery discharge can damage the card.
• 🔍 Check the map for errors via PC (Chkdsk tool in Windows).

Pay special attention to the type of card: cheap no-name drives often have understated real capacity, you can check this with H2testw (Windows) or SD Insight (Android). If the real volume is smaller than the declared, formatting will not help — the card is defective.

Method 1: Formatting through Xiaomi settings

The easiest method is to use the built-in MIUI tools, which are suitable for cards that the phone recognizes but doesn't work well.

1. Open the Settings → Storage.
2. Put it on your memory card (for example, SD-map: 128GB).
3. Select Format → Format as internal storage (if you need to expand memory) or Format as portable (for normal use).
4. Confirm the action. It takes 1-5 minutes depending on the volume.

⚠️ Note: When you select the option as internal storage, the card will be encrypted and tied to this device. Once removed, you will not be able to read it on another phone or PC without resetting it.

Backup copy of data created

The card is not used as internal storage in another device.

The device is charged or connected to charging

The correct formatting type (portable/internal) is selected

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Method 2: Formatting with Recovery Mode

If the card is not detected in the system or the phone is an error "SD-Map damaged, try formatting through recovery mode, and this method will work even on locked or "hang" drives.

Steps:

1. Turn off your smartphone.
2. Press Volume Up + Power before the Mi logo appears.
3. In the Recovery menu, select Advanced → Format SD Card (navigation with volume buttons, confirmation – power button).
4. Once completed, restart the device (Reboot System).

🔹 Important: In some firmware (MIUI 13 and older) Format paragraph SD Card may not be available. In this case, use Wipe & Reset → Wipe SD Card.

Method 3: Formatting via PC (Windows/macOS/Linux)

If your phone refuses to format a card, connect it to your computer through a card reader, which gives you more control over the process, including the choice of file system.

For Windows:

1. Insert the card into the card reader and connect to the PC.
2. Open this computer, find a removable disk (e.g., Disk E:).
3. PKM on the disk → Format.
4. Select the file system: FAT32 - for cards up to 32 GB (maximum file size 4 GB). exFAT - for cards from 64 GB (supports files > 4 GB, optimal for Xiaomi). NTFS - not recommended for Android (may not be readable).

Start.

For macOS/Linux, use the Disk Utility or the mkfs command in the terminal. For example, for exFAT:

sudo mkfs.exfat -n "MI_SD" /dev/sdX1

Where sdX1 is your card ID (you can find out the lsblk command).

💡

If Windows says, "Windows fails to complete formatting," try the SD Formatter utility from the SD Association, which bypasses the limitations of the standard tool and supports low-level formatting.

File System Choice: What’s Best for Xiaomi

The file system is responsible for card speed, device compatibility, and file size limitations. Xiaomi has three options:

⚠️ Note: If you use the card as internal storage (Adoptable Storage option), MIUI Automatically converts it to an encrypted partition. ext4. It's not compatible with other devices, and to get the map back to its original state, you'll have to format it on a PC.

Common mistakes and their solutions

Even after formatting, the map may not work properly, and let's look at the typical problems and ways to fix them:

• 🚫 "SD-The card is not supported" - check if your Xiaomi model supports cards of this size. 9A Officially only works with cards up to 512 GB, although it can physically take 1 TB.
• 🐢 Slow write/reading – the reason may be the card’s speed class (make sure it’s not lower than Class 10 or more) UHS-I). Also check if the option is not included Battery Savings in the settings MIUI — It limits the performance of flash memory.
• 🔄 The card is constantly unmounted - try to disable Automatic mounting SD in the developer settings (Settings) → The phone. → Version. MIUI — Tap 7 times to unlock).

If the map is detected but files disappear after the reboot, the cause may be a corrupted partition table, in which case low-level formatting via HDD Low Level Format Tool (Windows) or dd on Linux will help:

sudo dd if=/dev/zero of=/dev/sdX bs=1M count=100

This command will fill the first 100 MB cards with zeros, destroying all partitions, and then create a new partition using GParted or standard OS tools.

💡

If the memory card is no longer defined after the MIUI update, try rolling back the firmware or resetting your phone. Some versions (such as MIUI 14.0.4) have bugs with external drives.

FAQ: Frequent questions about map formatting on Xiaomi