When you connect the SD card to your smartphone Android, the system automatically creates a complex folder structure on it - some of them are visible to the user, others are hidden and used only by applications or the OS itself. SD card root is the top level of this hierarchy, a kind of “base” from which all other directories extend. But why does this section raise so many questions? The fact is that not all files here are obvious: some of them are responsible for the application cache, another for system settings, and the third may even turn out to be “garbage” left after deleted apps.

Many users encounter problems when trying to clear the root directory: either the files are not deleted, then after cleaning applications stop working, or suddenly access is lost to multimedia. All this is due to the fact that Android actively uses the SD card not only for storing user data, but also for official purposes. For example, the folder .android_secure contains encrypted application data, and the directory Android/data contains the cache and game settings. Deleting such files manually can lead to failures, so it is important to understand which folders can be touched and which are best left untouched.

In this article we will look in detail at:

What is the root of an SD card and how it works

Root directory (or simply root) is the topmost folder on the SD card and has no parent directory. If you imagine the structure of the map in the form of a tree, then the root is the trunk from which branch folders extend. In Android the root of the SD card is usually designated as /storage/XXXX-XXXX/ (where XXXX-XXXX is the unique identifier of the card) or simply /sdcard/ in some firmware. However, the physical path may differ depending on the OS version and device manufacturer.

Here are the key features of the root directory:

  • 📁 Contains all folders and files, including hidden ones (their names begin with a dot, for example, .thumbnails).
  • 🔒 Has access restrictions: some system folders cannot be opened without rights root or special applications.
  • 🔄 Dynamically changes: applications and the system constantly create/delete files in the root (for example, log files or temporary data).
  • ⚠️ Sensitive to errors: improper deletion of files can disrupt the operation of applications or even the OS itself.

For example, if you connect an SD card to a computer via a card reader, you will see something like this structure:



├── DCIM/ # Photos and videos from the camera


├── Download/ # Downloaded files


├── Android/


│ ├── data/ # Application data


│ ├── obb/ # Additional game files


│ └── media/ # Multimedia of some applications


├── .thumbnails/ # Thumbnail images (hidden folder)


├── .android_secure/ # Encrypted data applications


└── LOST.DIR/ # Recovered files after failures

Pay attention to the folder LOST.DIR - this is not garbage, but a system directory where Android saves files recovered after incorrect removal of the card or failure. It is not recommended to delete it, as it may be needed to restore data in the future.

📊 What do you most often use an SD card on your smartphone for?
Storing photos and videos
Installing applications
Transferring data between devices
Backup
Another option

What files and folders are stored in the root of the SD card

In the root directory you can find a variety of types of files - from regular user data to service data that you don’t want to touch. Let’s look at the main categories:

File/folder type Examples Is it possible to delete Consequences of deletion
User data DCIM/, Download/, Music/ Yes Loss of personal files (photos, music, etc.)
System folders Android/, LOST.DIR/ No Crashes in applications or OS
Hidden folders .thumbnails/, .android_secure/ Partially Degraded performance or application errors
Cache and temporary files .cache/, files with the extension .tmp Yes, but be careful Applications can recreate the cache, but there may be delays in the next startup

Hidden folders and files (those that begin with a dot) deserve special attention. For example:

  • 📸 .thumbnails/ — stores thumbnails of images for quick loading in the gallery. Deleting this folder will not harm, but the gallery will take longer to load the next time you open it.
  • 🔐 .android_secure/ — contains encrypted data of applications transferred to the gallery. SD card (function Adoptable Storage in older versions Android). Deleting will lead to the loss of this data.
  • 📱 .estrongs/ — temporary files of the file manager ES File Explorer. You can delete them, but they will appear again the next time you use the app.
💡

If you you see files with the extension .nomediain the root of the SD card, do not delete them! These files inform Androidthat the folder does not need to be scanned for multimedia (for example, so that photos from instant messengers do not end up in the gallery).

Files with unusual names may also appear in the root, for example:

  • autorun.inf — often created by viruses for autorun on Windows. On Android it is useless and can be deleted.
  • desktop.ini —Windows service file, can be deleted.
  • .Trashes — folder for the "recycle bin" on macOS. Not used. Android not used.
💡

Do not delete files with unknown extensions (for example, .dex, .oat) - they may belong to system applications or games.

How to open the root of an SD card on Android: step by step instructions

Access to the root directory of an SD card can be obtained in several ways. Let's consider the most reliable and safe methods.

Method 1: Through a standard file manager

Most smartphones on Android have a built-in file manager. manager (for example, Files by Google, Mi File Manager on Xiaomi or My Files on Samsung). To open the root of the SD card:

  1. Open the application Files (or similar).
  2. In the side menu, select SD card or External storage.
  3. You will find yourself in root directory. All folders and files will be displayed here, except hidden ones.

Method 2: Through third-party file managers

Applications like Solid Explorer, FX File Explorer or Total Commander provide advanced capabilities, including access to hidden files For example, in Solid Explorer:

  1. Open the application and grant access to the storage.
  2. In the top menu, click on the three dots → Settings → Show hidden files.
  3. Return to the root directory SD cards - now you will see all folders, including those starting with a dot.

Back up important data|Make sure the card is not being used by applications|Disable auto-sync (for example, Google Photos)|Check the free space on the card (at least 10% of the volume)-->

Method 3: Via PC (Windows/macOS/Linux)

If you need to perform complex operations (for example, data recovery), it is more convenient to connect the SD card to the computer:

  1. Remove the card from the smartphone and insert it into the card reader.
  2. Connect the card reader to the PC The system recognizes the card as removable. drive.
  3. Open This computer (Windows) or Finder (macOS) and go to the SD card drive.
  4. To see hidden files:
    • In Windows: View → Hidden elements.
    • In macOS: Finder → Keyboard shortcut Command + Shift + (dot).
    • In Linux: Ctrl + H in any file manager.
What to do if the PC does not see the SD card?

If the computer does not recognize the card, try the following steps:

1. Reconnect the card reader or use a different USB port.

2 Check the card on another device (for example, on another. smartphone).

3. Use the utility Disk Management (Windows) or Disk Utility (macOS) to check whether the card is recognized as a disk.

4. If the card is detected but does not open, the file system may be damaged. In this case, formatting will help (but all data will be lost!).

Important: if you connect the SD card to a PC, Do not remove it without safely disconnecting (use the function Remove the device in Windows or Eject in macOS). Otherwise, the file system may be damaged, and the card will no longer be readable on the smartphone.

Dangerous operations: what not to do in the root of the SD card

Working with the root directory requires caution. Even a seemingly innocent action can lead to serious problems. Here is a list of operations that strongly not recommended perform:

⚠️ Attention! If you use an SD card as internal memory (function Adoptable Storage in Android 6.0+), then any changes in the root directory can lead to complete inoperability of the card. In this case, it will have to be reformatted, losing all data.
  • 🗑️ Delete folder Android/ —this will lead to the loss of application data, including game saves and app settings.
  • 🔄 Rename system folders (for example, DCIM v Photos) - many applications will stop working correctly.
  • 📛 Change access rights (chmod) to system files without rootrights - this may block access to the card.
  • 🖥️ Format the card via PCif it is used as internal memory in Android the smartphone will no longer recognize it.
  • 📂 Delete a file .nomedia in messenger folders (for example WhatsApp or Telegram) - this will lead to filling the gallery with unnecessary media files.

It is especially dangerous to interfere with the operation of the folder. .android_secure. It contains encrypted data of applications transferred to the SD card in older versions Android (before 7.0). If you delete its contents, applications that use this function will no longer run. In new versions Android (8.0 and higher), this folder may be empty, but you still shouldn’t touch it.

Another common mistake is deleting files with the extension .db or .dat. These files often belong to application databases (for example, Google Maps stores the map cache here). Deleting them will not harm the system, but may reset app settings or force them to recreate the cache, which will take time and Internet traffic.

💡

If you are not sure whether you can delete a specific file or folder, move it to a separate directory (for example, Temp/) and check if there are any problems with the smartphone. If everything is fine, the files can be deleted after 1-2 days.

How to clear the root of an SD card without risk to the system

If you need to free up space on the SD card, do not delete files at random. Instead, follow a proven algorithm:

Step 1: Delete unnecessary user data

Start with the obvious:

  • 📷 Go to the folder DCIM/ and delete unnecessary photos/videos (for example, screenshots or duplicates).
  • 🎵 In the folder Music/ or Downloads/ check old downloads.
  • 📄 Delete documents (PDF, DOCX, etc.) that are no longer needed.

Step 2: Clear the application cache

Many apps store a cache on the SD card. To clean it safely:

  1. Go to Android/data/.
  2. Find folders with application names (for example, com.whatsapp for WhatsApp).
  3. Inside each folder there will be a subdirectory cache/ - you can clean it (but do not delete it application folder!).

Step 3: Use specialized utilities

Applications like SD Maid or CCleaner can automatically find and delete unnecessary files (duplicates, empty folders, remnants of deleted apps:

  • Back up your important data.
  • Do not give utilities access to system folders (mark only Downloads, DCIM etc.).
  • Check reviews of the app - some "cleaners" can delete necessary files.

Step 4: Check the LOST.DIR folder

This folder contains files recovered from crashes. Usually they are damaged and unnecessary, but sometimes there may be important data there. Before cleaning:

  1. Open LOST.DIR/.
  2. Check the files for valuable information (for example, photo).
  3. If there is nothing useful, the folder can be cleared (but do not delete the folder itself!).
💡

If you often connect the SD card to different devices, create a folder in the root Temp/ and transfer suspicious files there before deleting. This way you can restore them if something goes wrong. so.

What to do if the SD card stops working after changes in the root

If, after manipulating files in the root directory, the SD card is no longer detected or produces errors, do not panic. In most cases, the problem can be solved.

Situation 1: The card is not readable on the computer. smartphone

Try the following steps:

  1. Restart your smartphone.
  2. Remove the card and insert it back (with the phone turned off).
  3. Test the card on another device. If it works, the problem is in the smartphone (possibly the card slot). contaminated).
  4. If the card is not readable anywhere, try connecting it to the PC and running an error check:
    • V Windows: open Disk Properties → Tools → Check.
    • B Linux: use the command fsck /dev/sdX (where sdX is your disk).

Situation 2: Applications do not see files on the card

If, for example, a gallery stopped showing photos or the music player does not find tracks:

  1. Check whether you deleted the file .nomedia in folders where it should not be.
  2. Reboot the device - sometimes Android does not immediately update the media index.
  3. Use an application like Rescan Mediato force update the media file database.
  4. If the problem is in a specific application (for example, WhatsApp does not see files), reinstall it.

Situation 3: The card requires formatting

If the system prompts you to format the card, this means that the file system is damaged. Do not agree immediately — first try to recover the data:

  1. Connect the card to the PC and use recovery apps (for example, Recuva, PhotoRec).
  2. If the data is not are critical, format the card in FAT32 or exFAT format (not NTFS - Android does not support this file system for SD cards).
  3. After formatting, check the card for errors (as described above).
    4. ⚠️ Attention! If the SD card was used as internal memory (function Adoptable Storage), formatting via a PC will make it unsuitable for further use in Android. In this case, you can format the card only through the smartphone settings: Settings → Storage → SD card → Format as internal storage.

    FAQ: Frequently asked questions about the root of the SD card on Android

    Can I move applications to the root of the SD card without root access?

    In modern versions Android (8.0 and higher), transferring applications to an SD card is very limited. You can:

    • Use the function Adoptable Storage (turns the card into an extension of the internal memory, but then it cannot be removed without loss data).
    • Transfer only part of the data of some applications (for example, game cache through Settings → Applications → Storage).

Full transfer of applications (as in Android 6.0) is now possible only from root-rights or on some custom firmware.

Why do files with names like ._img123.jpg?

Create these files when copying data to the card? They contain metadata (for example, photo tags) and are not needed on macOS when copying data to the card. They contain metadata (such as photo tags) and are not needed on Android. They can be safely removed - they do not affect the operation of the smartphone. To prevent them from appearing again, before copying files from Mac disable the creation of metadata in the settings. Finder.

How to hide a folder from the gallery without deleting it?

Create an empty file in the folder with the name .nomedia (without extension). For example:

  1. Open any text editor (for example, Notepad++ or Notepad).
  2. Save an empty file with the name .nomedia (select the "All files" type when saving).
  3. Move this file to the folder that you want to hide from the gallery.

After that Android will stop scanning this folder on multimedia.

Is it possible to change the path to the root of the SD card (for example, from /storage/1234-5678 to /sdcard)?

No, the path to the SD card is determined by the system and depends on:

  • Version Android.
  • Device manufacturer (for example, Samsung and Xiaomi may have different paths).
  • Type of card connection (external or internal memory).

You can create a symbolic link (requires rootrights), but this will not change the real one path, but will only add an alternative access method.

Why is the space not freed up after clearing the root of the SD card?

This can happen for several reasons:

  • The files are occupied by the process (for example, the application is using the cache. Close all apps and restart the smartphone.
  • You are deleting). files, but they end up in recycle bin (some file managers work this way). Empty the recycle bin.
  • There are hidden system files on the card that are not displayed. Use DiskUsage or a similar application to analyze the occupied space.
  • The file system is damaged. Check the card for errors via a PC.