Owners of Xiaomi, Redmi and POCO smartphones often face cryptic notifications of memory shortages or see folders in the file manager that cannot be removed. In the Android operating system, as well as in the add-on MIUI or HyperOS, there is a whole layer of data hidden from the eyes of the average user. These are not just garbage, but system files that keep the device running.
Trying to “free up space” by manually deleting this data often leads to app crashes, icons disappearing, or even a system failure to boot altogether. Removing the system kernel or the framework’s libraries can turn a smartphone into a “brick” requiring reflashing through a computer. It’s therefore crucial to understand what each component is responsible for before deciding to clean it.
In this article, we will take a closer look at the internal memory structure, look at the contents of the Android folder and find out which processes can be safely stopped and which ones can be touched strictly, learn how to distinguish cache from critical data and understand the logic of the file system of your gadget.
The operating system on which Xiaomi smartphones are based uses a file system different from the usual Windows. There are no C: or D: disks, but there is a root directory and a set of folders, each of which has a strictly defined purpose. The Root partition contains the system kernel, which is responsible for booting and interacting with the hardware. User data is usually stored in the partition. /sdcard or /storage/emulated/0. This is where you go when you open the file manager, but inside this section, there are folders that are restricted by the superuser's permission, and trying to change their structure without the Root rights will result in the system being denied access. MIUI Adds its own layers on top of pure Android.This means that in addition to the standard system files, you have the files of the theme, battery optimization and Xiaomi services. They can take up a significant amount of space, but are critical for the correct operation of the interface. 💡System files are not garbage, but a “skeleton” of the operating system, the removal of which violates the functionality of the device.
The biggest questions users have are the Android folder, which is at the root of internal memory. Inside it are three key subfolders: cache, data and obb. Let's take a closer look at their purpose, because this is where the answer to the question "what takes up space?" The cache folder contains temporary files that applications create to quickly load content. In theory, it can be cleaned, but in modern versions of Android, the system does this automatically when memory is scarce. Manual cleaning here often does not give a long-term effect, since applications will simply create a cache again. More important are the folders for the development of the application, data, the data files, the data files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the data, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files, the files Deleting the contents of these folders is equivalent to completely resetting a particular application to a factory state. Let’s consider the main differences between these directories in the table below: Folder Purpose Deletion Consequences Cache Recommendation Temporary files to accelerate Safe, the application will reboot data Can be cleaned through the settings obb Game resources and heavy applications will stop running, will need to download Do not manually delete data Saving, settings, Accounts Loss of progress, reset application settings Categorically do not touch 💡If the game requires an update or gives an error after cleaning the obb folder, simply delete it completely and download it again through Google Play.
In addition to the memory part visible to the user, Xiaomi smartphones reserve hidden partitions, which include boot, recovery, system and vendor, accessed only through Fastboot or TWRP. The vendor section is especially important for Xiaomi devices, as it contains proprietary camera, screen and model drivers optimized by the company’s engineers. Damage to this partition when trying to "flash" the phone often results in a camera or no communication, even if the system boots. Users trying to get Root rights often modify the system partition. MIUI, which cannot be removed by standard means. However, this procedure deprives of warranty and can disrupt the operation of banking applications due to the integrity check. What is the persist partition?The persist partition stores calibration data for sensors (accelerometer, gyroscope, proximity), its removal or damage leads to the inoperability of sensors, and it is almost impossible to restore them software without factory calibration.