Xiaomi smartphone owners often face the need to expand internal storage, especially on models such as the Redmi 9. Standard volume of 64 or 128 gigabytes may not be enough for a large number of photos, high-resolution video or heavy games.
However, once the drive is physically installed, MIUI does not automatically grant all applications full read and write rights, and this is done for security reasons so that malware can’t damage your files, so users often have to manually configure permissions, format media, or change the type of storage.
In this guide, we will go into detail all the stages of configuration, from the initial formatting to fine-tuning access rights for specific programs, and you will learn how to turn a flash card into a full-fledged extension of internal memory or use it as a universal external drive.
Primary configuration and formatting of the drive
Before the system allows applications to work with a new media, it must be formatted correctly. When you first install a card, Redmi 9 usually gives a notification of the discovery of a new device. This step cannot be ignored, since without an exFAT or FAT32 file system, the phone will not be able to record data correctly.
The formatting process cleans the map completely by deleting all old files, so save important data on your computer beforehand. Once this procedure is complete, the Android operating system will create the necessary folder structure for system files, media and application cache.
⚠️ Warning: During the formatting process, a warning may appear that all data will be destroyed, make sure there is nothing important on the map, or back up before the operation begins.
If the automatic notification doesn't appear, you can force the process through the settings. Go to the Settings menu, then select About Phone and click on Warehouse. From the list of available drives, find your memory card and select the formatting option.
☑️ Preparation of a memory card
Type of use: Portable or Internal
One of the key features of modern versions of Android is the ability to choose the type of drive you use. When you set up Redmi 9 will offer two options: use the card as a portable storage or as internal memory, and this choice directly depends on how applications access files.
Portable storage is a classic mode where the card works like a flash drive, you can insert it into any other phone or computer and read the data, but applications cannot be installed directly on it without additional manipulation, and access to files can be limited by Android 10/11 access rights.
The Adoptable Storage mode encrypts the card and links it specifically to your smartphone, and it won't read on another device, but it can transfer the cache and application data to it, effectively expanding the system partition, which solves the problem of not having enough space to install programs.
| Parameter | Portable storage | Internal memory. |
|---|---|---|
| Compatibility | Readable on any device | Only on this phone. |
| Installation of applications | Limited or impossible | Full support |
| Security | Standard. | Encryption of data |
| Speed of operation | Depends on the class of the card. | Requires a high-end card (A1/A2) |
Which card class should I choose for internal memory?
How to provide access to files on SD-map
In Android versions above version 10, Google has significantly tightened its file system access policy, so apps can’t just read all files on a memory card, and if you install a new file manager or video player, it may not see your videos or music until you manually give it permission.
To grant rights, you need to go to the settings of a particular application. Go to Settings -> Applications -> All applications. Find the desired program (for example, VLC or MX Player) in the list and select Permissions or Rights.
Here you are interested in Files and Media (or Memory in older versions of MIUI); the default option is to ban or allow only media files.
- 📂 Open the settings of a particular application through the main menu of the smartphone.
- 🔐 Find the “Permissions” section and select access to files.
- ✅ Activate the switch to Allow all files to be managed».
- 🔄 Restart the application to make the changes effective.
Sometimes the system can redirect you to a special section of the security settings, in which case follow the on-screen prompts to confirm the action, and without this step, many modern programs will simply refuse to function correctly.
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If the application doesn’t see files even after permission, try clearing its cache in the Apps section –> Memory –> Clear the cache.
Solving Access Problems and Reading Errors
Despite the correct setup, Redmi 9 users may encounter errors such as “File corrupted” or “Resolution required.” Often the problem is not the software settings, but the file system or physical contact. The map could be formatted in NTFS format, which Android cannot read without special drivers.
It's also worth checking if the card sits tight in the tray, and vibration or dust can disrupt the contact, and if the phone periodically writes "Map damaged," try removing it, erasing the contacts, and pasting it back until the characteristic click.
⚠️ Warning: Do not remove the memory card at the time of writing data.This can lead to corruption of the file system and data loss, after which the phone will require re-formatting.
If the software methods don't work, you can try using a computer. Connect the card through the card reader and check it for errors with Windows. In the disk properties, select the Service tab and click Check.
Transferring data and applications to a memory card
Once access is allowed, it becomes logical to transfer heavy files. Xiaomi Redmi 9 allows you to transfer photos, videos and music through a standard Explorer. Just select files, select Move and specify the path to the file. SD-map.
Applications are more complicated, not all programs support external storage, and developers decide whether they can be installed on the external drive. SD-If possible, the "Move" button will be active in the app menu.
To transfer data, perform the following actions:
- 📁 Open the standard Files Explorer on your desktop.
- 📂 Go to “Internal Storage” and find folders. DCIM, Download, Music.
- ✂️ Select the files you need and select “Move».
- 💾 As a destination, indicate yours. SD-map.
Using a memory card helps free up precious internal space, which has a positive effect on the overall speed of the smartphone, and the system starts to work faster when the free amount of internal memory exceeds 15-20%.
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Regularly clean internal storage by transferring media files to SD-Card is the best way to prevent braking of the smartphone.