How to format the flash drive on the phone Xiaomi Redmi Note 9: 3 proven ways

Formatting a flash drive on a Xiaomi Redmi Note 9 smartphone can be needed in a variety of situations, from preparing the drive for the first use to eliminating read errors or changing the file system. Despite the apparent simplicity of the procedure, many users face difficulties - the phone does not see the flash drive after formatting, the process is interrupted or errors occur. In this article, we will analyze all working formatting methods, including hidden MIUI functions, and explain why standard methods sometimes do not work.

The Redmi Note 9 has a limited ability to use a full-time file manager compared to a PC. There are no usual options like file system selection (FAT32, exFAT, NTFS) or low-level formatting. However, this does not mean that the task is impossible. We will show you how to get around the restrictions through embedded tools, third-party applications and even with the help of a computer if the phone refuses to work with the drive. It is important to consider that the wrong actions can lead to data loss or damage the USB drive - so make a backup of important files before starting the procedure.

Why you can’t format a flash drive on Redmi Note 9

Formatting problems on the Xiaomi Redmi Note 9 are most often due to three factors: file system incompatibility, physical damage to the drive or the limitations of the MIUI firmware.

First, a smartphone may not recognize flash drives with an NTFS or exFAT file system if they were formatted on a PC. MIUI only supports FAT32 for external drives by default, and trying to write files larger than 4 GB to such a flash drive will lead to an error. Second, if the drive was previously used in cameras, recorders or other devices, it may receive non-standard markup that the phone does not know how to handle correctly. Finally, physical defects (for example, damaged sectors) or software failures in the USB drive controller make it unsuitable for format through standard means.

• 🔍 The file system is not supported: MIUI not working NTFS and sometimes with exFAT without additional settings.
• 🛠️ Damaged sectors: The flash drive can be “broken” – in this case, only a replacement will help.
• 📱 Limitations MIUI: Firmware blocks some operations with external drives for security reasons.
• 🔌 Low-quality adapter: If you use it OTG-cable, the problem may be in it, not the flash drive.

Before you start formatting, check the performance of the flash drive on another device (for example, on a PC or laptop). If it is not detected there, the problem is in the drive itself. If it is detected but not formatted, try the methods described below. Also make sure that the adapter is not detected there. USB-C/OTG Connect to the phone another flash drive or mouse via the same cable.

Method 1: Formatting through a standard MIUI file manager

The easiest method is to use the built-in Xiaomi file manager. It does not provide advanced options, but will cope with the basic task if the flash drive is working and has been used on Android devices before. MIUI 12-14 on the Redmi Note 9.

Connect the flash drive to the phone through OTG-adapter (if you use a microSD, insert it into the slot). Once the notification of the drive connection appears, follow the following steps:

1. Open the Files app (the folder icon on the home screen or in the app menu).
2. In the "Device" section, find your flash drive - it can be called "USB-drive" or display a model (e.g., "SanDisk Ultra").
3. Press three points ("⋮") in the upper right corner and select "Settings".
4. Scroll down to the "Additional" section and tap "Format".
5. Confirm the action, wait for the process to be completed (usually takes 10–30 seconds).

If the Format option is inactive or not, it means that MIUI does not recognize the flash drive as a removable drive. Try to remove and reconnect it or use alternative methods from the following sections.

Make a backup copy of data from the flash drive|Check the connection. OTG-adapter|Make sure that the flash drive is defined in the "Device" section"|Charge your phone at least 30 times%-->

⚠️ Note: Standard formatting through MIUI always FAT32. If you need exFAT (for example, for files) >4GB), this method won't work - go to Method 3.

Method 2: Use the Settings app for microSD

If you format a microSD card inserted into the Redmi Note 9 slot, you can use the phone's settings menu. USB-You can't format your flash drives through it, but you can use the "Inner Memory" option here, which allows you to use the card as part of your main storage (similar to Adoptable Storage in pure Android).

To format microSD as a removable drive:

1. Go to Settings. → Memory.
2. Tap on the name of your memory card (for example, "SD-64GB").
3. In the upper right corner, press three dots ("⋮") and select "Storage settings".
4. Click "Format" → "Format as a removable medium".
5. Confirm the action and wait until it is completed (may take up to a few minutes).

If you need to use the card as internal memory (for example, to install applications), select the corresponding option in step 4. Note that after that the card will not be retrieved without losing data - it will be encrypted and tied to the phone. This mode may not be supported on some versions of the Redmi Note 9 (for example, on models with a hybrid slot under two). SIM-map).

⚠️ Note: Formatting a microSD as internal memory leads to encryption, so if you then reset your phone to factory settings, all data on the card will be deleted without recovery.

Method 3: Formatting through third-party applications

If the built-in MIUI tools fail, third-party tools will come to the rescue, allowing you to select a file system, perform low-level formatting, or repair damaged sectors. We recommend two proven applications: the USB OTG Format Tool and the SD Card Formatter (from the official developers of the SD Association), both available on Google Play and compatible with the Redmi Note 9.

Let’s look at the SD Card Formatter:

1. Install the app from Google Play.
2. Connect the flash drive to the phone through OTG-adapter.
3. Run the utility and select your drive in the list.
4. File system: FAT32 for compatibility with most devices; exFAT for files larger than 4GB

"Format"

The advantage of this method is the ability to choose exFAT, which is impossible through standard means. MIUI. The app also shows the SMART-If the process ends with an error, try the option "Overwrite format" (complete erasure of data).

💡

If the application does not see the flash drive, try to disable Battery Optimization for it in the MIUI settings. Go to Settings → Applications → Application Management → SD Card Formatter → Battery → No restrictions

For low-level formatting (if the flash drive is defined but not formatted), the HDD Low Level Format Tool is fine. It needs to run on a PC, but it can repair even badly damaged drives. Importantly, it erases all data without recovery, including the controller's service information.

Method 4: Formatting via computer (if the phone is not working)

If none of the above methods worked, the last option is to plug the flash drive into the computer and format it there, which is especially true for NTFS or custom markup drives.

• 💻 Computer with Windows/macOS/Linux;
• 🔌 card reader OTG-adapter;
• ⚡ Formatting software (e.g. Rufus or DiskPart).

Step-by-step instructions for Windows:

1. Connect the flash drive to the computer.
2. Open Disk Management (click Win + R, enter diskmgmt.msc).
3. Find your flash drive in the list, right-click and select "Format".
4. Specify the file system (FAT32, exFAT or NTFS) and click OK.

For low-level formatting, use Rufus:

1. Download the program from the official website.
2. Select a flash drive in the list of devices.
3. In the File System section, specify FAT32 or exFAT.
4. Press "Start" and wait until it's finished.

If the flash drive is not detected even on a PC, try the DiskPart utility:

diskpart


list disk




select disk X (where X is your flash drive number)




clean




create partition primary




format fs=fat32 quick




exit

How to avoid formatting errors on Xiaomi Redmi Note 9

Even after successful formatting, Redmi Note 9 users sometimes run into problems: the flash drive is not mounted, data is not saved or write speeds fall.

• 🔄 Use Safe Retrieval: Always disable the USB drive through the notification menu, rather than just pulling it out.
• 📱 Update. MIUI: In new versions of firmware improved support for external drives.
• 🛡️ Check for viruses: Some malware blocks access to flash drives.
• 🔋 Watch for battery power: Interrupting process due to phone discharge can damage file system.

If the flash drive is slow after formatting, try:

• Format it on a PC with the choice of "Fast (clean table of contents)" instead of full formatting.
• Use the exFAT file system instead of FAT32, which is better optimized for larger files.
• Check the read/write speed with the A1 SD Bench app (available on Google Play).

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If the flash drive is defined as “damaged” after formatting, try formatting it on a PC with allocations unit size = 4096 bytes, which often solves compatibility problems on Android devices.

Frequent questions about formatting flash drives on Xiaomi