How to access the file system on Android: from beginner to pro

Mobile devices based on the Android operating system provide users with enormous freedom of action, but the standard interface often hides deep data storage structures. Many enthusiasts and advanced users are faced with the need to edit system files, remove unremovable junk, or fine-tune settings hidden from the naked eye. Understanding how your gadget works is the key to complete control over the device. file system of your gadget is the key to complete control over your device.

Unlike desktop operating systems, Android is designed with security in mind, which places certain restrictions on access to critical sections of memory. The average user sees only the tip of the iceberg, while the main processes and settings are hidden in protected directories. In this material, we will analyze in detail all the known methods of penetrating into the depths of the operating system, assess the risks and select the most effective tools for your specific situation.

Before taking active steps, you need to clearly understand the difference between the user space and the system partition. Improper handling of the latter can lead to serious consequences, including complete inoperability of the smartphone. Therefore, every step should be meaningful, and backing up important data will be your first and most important task before starting any manipulations.

Data storage structure and access levels

The fundamental difference between Android and Windows is the use of the Linux file system, where everything is presented in the form of a directory tree, starting with the root directory /. In standard operating mode, the user has access only to a limited set of folders, such as /sdcard or /storage/emulated/0, where media files and application documents are stored. System partitions, such as /system, /data and /vendor, are by default closed for writing and often even for reading without special privileges.

There are several access levels that determine what operations you are allowed to perform. The basic level only allows you to view the contents of user memory. The next level, often called ADB access, makes it possible to send commands via USB debugging, which opens access to logs and some system functions, but does not allow modification of protected partitions. Aerobatics is getting root access (superuser), which removes all restrictions.

It is important to understand the architecture of memory partitions, since different smartphone models may have differences in the layout. For example, on modern devices with the implementation of the Treble project, the partition structure has become more modular, which makes it more difficult to directly interfere with system files without deep knowledge.

• 📂 /system —contains the main part of the operating system, applications and libraries that are critical for launching.
• 📂 /data —all user data, application settings and the operating system itself are stored here during operation.
• 📂 /cache —a temporary partition for caching of data, the clearing of which is safe, but can speed up the system.
• 📂 /sdcard - emulation of external memory, available to the user without restrictions.

⚠️ Attention: Direct modification of files in partitions /system or /boot without having a backup copy or knowing the exact syntax of configuration files can lead to a “bootloop” (cyclic reboot) of the device.

Differences in the implementation of the file system also depend on the manufacturer of the processor and shell. Devices based on Snapdragon and MediaTek may react differently to attempts to mount partitions in read-write mode. In addition, the introduction of encryption (FDE) or file-by-file encryption (FBE) in modern versions of Android makes direct access to data without an unlocked device almost impossible even with root access, unless the boot conditions are met.

Using file managers with extended rights

The easiest way to look deeper than the standard Explorer is to use specialized file managers, such as MT Manager, Root Explorer or Solid Explorer. These applications are able to request elevated privileges and, if available, display hidden system folders. However, it is worth remembering that without root access, the functionality of such apps is limited only by user space and the ability to analyze APK files.

To work with system files through a file manager, you must have superuser rights. After gaining root access (for example, via Magisk), the Explorer application will ask for permission to use these rights. After confirmation, you will be able to not only read, but also edit, delete or replace files in the root directories. This is convenient for quickly replacing system fonts, ringtones or editing configuration files build.prop.

However, even with root access, modern versions of Android (starting from 10 and higher) have implemented a mechanism Scoped Storagethat limits application access to files of other applications and system areas. This means that even an advanced file manager may not see some folders or will not be able to open them without additional manipulations through ADB or special scripts.

How does the Scoped Storage mechanism work?

Starting with Android 10, Google introduced Scoped Storage to isolate application data from each other. Now applications do not have free access to the entire file system, but work only in their sandboxes. Special APIs are used to access shared files, and the direct path to files of other apps is closed, which increases security but complicates life for enthusiasts.

When choosing a file manager, pay attention to the support for plugins and built-in code editors. The ability to highlight syntax for XML and JSON files greatly simplifies making changes to system configuration files. A low-quality editor can add extra encoding characters, which will lead to errors when loading the system.

Obtaining root access: necessity and risks

Obtaining superuser rights (root) is the classic and most comprehensive way to gain unrestricted access to the entire file system. The rooting process varies depending on the device model, bootloader version and manufacturer. The most popular and safe method today is to use Magisk, which allows you to gain root access in a system-safe way (systemless), without directly modifying the system partition.

The rooting procedure usually requires unlocking the bootloader, which is not officially allowed on all devices. For example, smartphones Huawei or carrier version devices in the US often have a locked bootloader that cannot be opened using legal methods. After unlocking via Fastboot, a modified recovery image (TWRP) is loaded or the boot_image is patched, which gives the desired rights.

It is important to consider that having root access opens the door not only for you, but also for potential threats. Malware that gains root access can completely take control of the device, intercepting passwords and banking data. In addition, many applications (banks, payment systems, games with anti-cheat) refuse to work on rooted devices, requiring complex bypasses through Magisk Hide or Zygisk.

Access method	Privilege level	Risk of loss of warranty	Complexity
Standard FM	Custom	None	Low
ADB (Wireless/USB)	Debug/Shell	No	Medium
Root (Magisk)	Full (Superuser)	High	High
Custom Recovery	Full access to partitions	High	High

Don't forget that unlocking the bootloader and getting root access almost always triggers security flags (for example, Samsung Knox), which permanently disables some device features, such as Secure Folder or Samsung Pay. Weigh all the pros and cons before starting the procedure.

Working with ADB and Fastboot without root access

Toolkit Android Debug Bridge (ADB) provides powerful capabilities for interacting with the file system without the need for root access. Using console commands, you can copy files between your PC and smartphone, delete system applications (for the current user) and access logs. This is the “golden mean” for those who are afraid of violating the warranty, but need advanced functionality.

To get started, you need to activate developer mode and enable USB debugging in the device settings. After connecting to your computer and installing the drivers, you can use commands like adb pull to extract files or adb push to download. The team is of particular value adb shell, which opens a terminal on the device, allowing you to execute scripts and manipulate files within the rights of the shell user.

adb shell pm uninstall -k --user 0 com.example.bloatware

This command, for example, allows you to remove a system application for the current user without affecting the system partition itself. The application disappears from the interface and stops consuming resources, but physically remains in the partition /system, which makes it easy to return it back with a factory reset. This is a safe way to “clean” the system of pre-installed junk.

However, ADB has its limitations. You will not be able to modify files in protected directories or change system libraries. Access to other app files is also limited by Android security policies. However, for 90% of optimization and file management tasks, this tool is quite enough.

Mounting partitions and working with Terminal Emulator

For those who prefer to work directly on the device, a terminal emulator becomes an indispensable tool, for example, Termux or Terminal Emulator for Android. These apps allow you to run Linux console commands directly on your smartphone. Combined with root access, this turns the phone into a full-fledged Linux computer, allowing you to mount partitions, change access rights (chmod/chown) and run scripts.

One ​​of the key tasks when working with the terminal is to mount the system partition in read-write mode. By default, the partition /system is mounted read-only (ro), which prevents accidental corruption. To make changes, you need to remount it:

mount -o rw,remount /system

After running this command (requires root), you will be able to edit files in the system folder. However, modern devices use dynamic partitions and an A/B system, which makes direct mounting difficult or impossible without using special Magisk modules or working in Recovery mode.

Use Termux also allows you to install full-fledged Linux packages (via proot), run servers, code compilers and even graphical interfaces. This opens access to the file system at a level close to desktop Linux, allowing complex data analysis and processing directly on a mobile device.

⚠️ Attention: The command rm -rf in a terminal with root access deletes files permanently and without confirmation. One mistake along the way can wipe out the entire system. Always double-check the path before pressing Enter.

Access via Recovery Mode and TWRP

When the system is booted, many files are locked by OS processes. The deepest access to the file system is possible through Recovery mode. The standard recovery mode is limited, but installing a custom recovery, such as TWRP (Team Win Recovery Project)gives full file access to all memory sections, including encrypted ones (after entering the unlock password).

TWRP has a built-in powerful file manager that allows you to copy, delete, rename and change file permissions. This is an ideal tool for backing up partitions /boot, /recovery or /persist before making changes, as well as for restoring the system in case of critical errors. You can connect to a PC in MTP mode directly from recovery and manage files through the computer.

In addition, through TWRP you can mount partitions and execute commands through the built-in console (Advanced → Terminal Command). This allows you to edit configuration files when Android itself does not boot. For example, you can remove the problematic Magisk module or fix errors in fstabthat interfere with loading.

Installing a custom recovery requires an unlocked bootloader and is often accompanied by a data reset. Recovery interfaces may differ depending on the version of Android and the device, so before starting work it is recommended to study the documentation specifically for your smartphone model.

What to do if TWRP does not see the internal memory?

Often the problem lies in encryption. Try formatting Data (Format Data) in the Wipe section by entering "yes". This will delete all data and remove encryption, after which the file manager in TWRP will work correctly.

Frequently asked questions (FAQ)

Is it safe to delete files in the /data/app folder?

Deleting files directly from /data/app may lead to errors in the registry of installed applications. The system will consider the application installed, but the files will be missing. It is better to use the command pm uninstall via ADB or standard deletion so that the system correctly updates its databases.

Is it possible to access the file system without a computer?

Yes, it is possible. A combination of root access, a file manager (for example, MT Manager) and a terminal emulator (Termux) allows you to perform 95% of file operations without connecting to a PC. However, for the initial setup (unlocking the bootloader, installing Magisk), a computer is usually required.

Why did banking applications stop working after getting root?

Banking applications use Google SafetyNet or Play Integrity API to check system integrity. Having root access and an unlocked bootloader violates this integrity. To bypass it, you need to use Magisk modules (for example, Zygisk and DenyList), which hide the fact of rooting from specific applications.

How to get everything back if I broke something?

If you have a custom recovery (TWRP), you can restore a full backup (Nandroid backup) made before the changes. If there is no backup, but the bootloader is unlocked, flashing the stock image boot.img and recovery.img via Fastboot, or a full reset and flashing the official firmware through the manufacturer's special utilities (Odin, MiFlash, SP Flash Tool) often helps.