Owners of Xiaomi, Redmi and Poco smartphones sooner or later face a mysterious notification that memory is full, or see in the system analyzer section "Big files" that takes gigabytes. This is puzzling, because the user could not download movies or heavy games, the phenomenon of accumulation of bulk data is characteristic of the shell MIUI and HyperOS, which aggressively cache content to speed up the application.
Ignoring this problem leads to a critical slowdown of the device, the inability to install updates and even malfunctions in the work of messengers. The system folder of big files often contains not only garbage, but also important application data, so blindly removing all content can lead to loss of progress in games or program settings. In this article, we will analyze the anatomy of the storage, explain the nature of the origin of such files and propose safe cleaning algorithms.
The nature of large files in the Android system
The Android operating system is designed so that each installed application tends to create its own area for storing temporary data, which is necessary for fast downloading of content that you view regularly, for example, social media feeds or video previews in messengers are stored on the disk so that when you reopen it, you do not waste traffic and time on downloading.
And over time, these caches grow to unimaginable sizes, and if you're using Telegram or WhatsApp, they can take up to a few hours. 10-20 GB of memory, storing all photos and video files ever viewed, and the system classifies them as "large files" because they exceed the standard size threshold for a conventional cache.
In addition to user-generated content, there are system logs and error reports, applications can create detailed logs of work that must be automatically deleted, but sometimes this mechanism fails, leaving gigabytes of technical text on the disk that is useless to the average user.
⚠️ Note: Do not attempt to delete files with the.apk extension or system libraries.so from the root folders of Android manually.This can disrupt the integrity of the operating system and lead to an endless reboot cycle (bootloop).
Why does memory fill up on its own?
Storage analysis: Where to look for spaces
First, you need to understand what is eating up your memory. Xiaomi smartphones have a powerful analysis tool built in, but it doesn’t always show the full picture. The standard way to check is to go to Settings → Memory or use the Security → Cleanup app.
However, for deep analysis, it's better to use the built-in file manager. Open the Files app (or Explorer), click on the menu icon (three bars) and select "Storage Analyzer." Here you'll see the visual distribution of space. The heaviest categories are usually marked in red or orange.
Note the app names folders. Often, the root of the internal memory are the Android, DCIM, MIUI, Tencent folders, and that's where the big files are hidden. Android/data folders can be as big as tens of gigabytes, because they store the caches of games and streaming services.
It's important to distinguish between user files and system files. If you see a file with a name like tencentvideo_cache_09283.dat size 2 GB, this is clearly a video from an app. error_report.zip — This is technical waste that can be safely removed.
System folders and application cache: what can be deleted
The largest part of the “big files” is usually hidden in the bowels of the Android folder, which contains two key directories: data and obb. The first stores application data (cache, logs, temporary files), and the second stores additional resources for games (textures, music, maps).
Cleaning the data folder is safe for most applications, but it will reset their settings and log out of their accounts, and you will have to re-sign in to social networks and messengers, but it frees up a huge amount of space, and you only have to touch the obb folder if you delete the application itself, otherwise the game will stop running.
For safe cleaning, it is better to use the regular system tools, not third-party cleaners. Go to Settings → Apps → All applications. Select a "heavy" application (for example, YouTube or TikTok), click Memory and then Clear Cache.
☑️ Safe cleaning of the cache
There is also a MIUI/Gallery/cloud folder that can store deleted photos before they are permanently erased from the cloud, and checking this directory often allows you to find several more gigabytes of lost space.
Garbage from messengers: Telegram, WhatsApp, Viber
The leaders in creating “big files” are certainly messengers. Telegram, for example, by default stores all media files in the memory of the phone. If you are in dozens of channels where you constantly post video, your phone becomes a repository of other people’s content.
To solve the problem, you need to change the settings of the application itself. On Telegram, go to Settings → Data and memory → Memory Use. Here you can limit the size of the cache or set up an automatic cleanup, for example, once every 3 days. This is the most effective way to fight.
On WhatsApp, the situation is similar. Go to Settings → Data and Storage. Turn off auto-save to the gallery, especially for group chats. You can also use Storage inside chats to see which dialogs are taking up the most space and delete old video files selectively.
| Annex | Location of the cache | Is it safe to remove? | Effects of cleaning |
|---|---|---|---|
| Telegram | Android/data/org.telegram.messenger | Yes (via settings) | We need to reload the media. |
| Android/media/com.whatsapp | Yeah (media files) | Gallery photos will be missing | |
| YouTube | Android/data/com.google.android.youtube | Yes. | Resetting recommendations |
| TikTok | Android/data/com.zhiliaoapp.musically | Yes. | Drafts could go missing |
⚠️ Note: When you clean your messenger data through your phone settings (Erase Data button), you delete all correspondence. Use only the Clear Cache function or the built-in cleaning tools inside the apps themselves.
Hidden folders and remnants of remote programs
Often users delete a game or application, but there are tails on the disk. Software developers do not always prescribe the correct delete script, leaving behind folders with configuration files and cache. They can lie there for months, taking up space.
Find folders with remote program names or weird names like com.company.game in the root directory if you know you have deleted the game, and check the Download folder, which often accumulates.apk installation files that are no longer needed after installing the programs.
To find duplicates and hidden large files, you can use the Cleanup feature in the Security app, which scans the system for residual files, but you shouldn't trust it 100% - you should manually go through the file manager and check the Download folder and the root of internal memory.
💡
Use size sorting in the file manager. In Files, click three dots, select Sort" →"The heaviest files will be at the top of the list, and you will immediately understand what you can delete.
Radical methods and reset to factory settings
If nothing helps and the memory fills up on its own even after cleaning, there may have been an error in the file system or a critical amount of system debris has accumulated that is not being removed by regular means, in which case the last resort is a complete reset.
Before you do that, make sure to back up all your important data to your computer or to the Mi Cloud/Google Drive cloud. Reset will delete absolutely everything: contacts, photos, apps and settings. The phone will return to the "store-like" state.
You can reset via the menu: Settings → About Phone → Settings Reset → Erase all data. After this procedure, the phone will work as fast as possible, and the problem with large files will disappear as the file system will be formatted again.
💡
Full reset is the only way to ensure that you remove system debris and file system errors that cannot be found manually.
Prevention of memory overflow
To keep the big file problem from coming back too often, you need to develop a digital hygiene habit: check the storage regularly, at least once a month, don't wait for the phone to slow down or give out space-short alerts.
Use cloud storage for photos and videos. Set up sync with Google Photos with Free Space, which removes images already uploaded to the cloud from your device, allowing you to keep only high-quality originals in memory and cache minimal.
It’s also worth disabling auto-update apps over the mobile network, leaving this feature only for Wi-Fi. Large game updates can unobtrusively download gigabytes of data in the background if you forget to switch.