Why Xiaomi Redmi 9 is constantly clogged memory: reasons and how to clean

Xiaomi Redmi 9 owners often face a problem: the smartphone memory is clogged in a matter of days, even though you haven’t downloaded anything. The system shows a warning about the lack of space, applications begin to slow down, and photos stop being saved. What is the reason? It’s not only the small amount of internal memory (32/64 GB), but also the features of the MIUI firmware, background processes and hidden files.

We analyzed typical scenarios and identified 7 key reasons why memory on Redmi 9 fills up on its own. In this article, detailed instructions on how to find and remove garbage, optimize system operation and prevent re-clogging. Pay special attention to the section on hidden MIUI cache, which is a unique feature of Xiaomi, which few people know about.

1. App cache: why it takes gigabytes

Cache is a temporary file that creates applications to speed up work. In theory, they should be cleaned automatically, but on Redmi 9 they often accumulate for months. For example, YouTube can eat up to 1-2 GB per video cache, and social networks can eat hundreds of megabytes per thumbnail.

Compounding the problem, MIUI by default limits automatic cache cleanup. Even if you manually clean memory through Settings → Memory, the system leaves some files “just in case.” Check the actual cache volume through the Settings menu → Applications → Application Management → [select application] → Memory.

• 📱 Social networks (Facebook, Instagram, TikTok): cache of images and videos – up to 500 MB per week.
• 🎵 Music services (Spotify, Yandex Music): cache of tracks - up to 1 GB.
• 🎮 Games (PUBG Mobile, Genshin Impact: Texture and Update Cache – Up to 3GB.

⚠️ Note: Do not clear the cache of system applications (e.g. com.android.systemui) - this can cause interface failures. Use only the option "Clear cache" and not "Clear data»!

MIUI and its hidden “gifts”: what is taking up memory without your knowledge

MIUI firmware is known for its "chips," but some of them work against the user. Here are three hidden mechanisms that eat up memory on Redmi 9:

1. MIUI backups: The system automatically creates backups of settings, SMS and logs. Files are stored in the MIUI/backup folder and can weigh up to 1-2 GB.
2. Error logs: MIUI keeps detailed logs (/data/log) that inflate to hundreds of megabytes when they fail.
3. Updates by Air (OTA): Updates downloaded but not installed take up to 1.5GB in the /cache folder.

To find these files, connect your smartphone to your PC and enable hidden folder display. Or use a root file manager (like FX File Explorer) that you can manually delete, but be careful: don't touch the system and vendor folders!

3. Duplicate photos and videos: how to find and delete them

Redmi 9 has a nasty feature: when you transfer files from a PC or cloud, you often create duplicates. For example, if you download a photo from Google Photos and sync it to MIUI Gallery at the same time, you get two copies of the same file. The same thing happens when you edit the photo: the original is saved, plus an edited version is created.

To find duplicates, use applications like Files by Google or CCleaner, which scan memory and show repeating files. Importantly, before deleting, check if the duplicates are versions of different resolutions (for example, the original + compressed copy for instant messengers).

Find all photos in DCIM, Pictures, Download|Sort by date or size |Use the duplicate app (e.g. Duplicate Files Fixer)|Check the.thumbnails folder – it stores thumbnails that can be safely removed |Recently Deleted

-->

Preventive tip: Turn off auto-saving media files in messengers. WhatsApp does this in Settings → Storage and Data → Media Auto-boot. Telegram – in Settings → Data and memory → Auto-boot.

4. Background processes and “zombie” applications

MIUI aggressively caches apps in memory even if you don't use them. Mi Video, Mi Music, or GetApps, for example, can take up to 300MB each, even though you never opened them. In addition, some apps (especially Chinese ones) continue to run in the background, consuming memory and battery power.

To stop the zombie processes:

1. Go to Settings → Applications → Application Management.
2. Select the app and click “Stop”.
3. To completely remove system applications, root or ADB rights will be required.

⚠️ Warning: Do not disable system services called com.android. or com.miui. - this can lead to system failure).

For advanced users: you can disable unnecessary system applications via ADB by command:

adb shell pm uninstall -k --user 0 title.packet

List of packages for safe removal with Redmi 9:

• com.miui.videoplayer – standard video player
• com.miui.player – Music player
• com.xiaomi.midrop - Mi Drop (if you don't use it)

5. Cloud syncs: how they clog memory

If you use Google Photos, Mi Cloud or Yandex.Disk, your Redmi 9 can download files in the background. For example, Google Photos defaults to save copies of all uploaded photos in the DCIM/Camera folder, even if the originals are already in the cloud. and Mi Cloud syncs notes, contacts and SMS, creating backup files in /data/com.miui.cloudservice.

How to fix it:

• 📁 In Google Photos, turn off “Save copies on your device” in sync settings.
• ☁️ In Mi Cloud, go to Settings → Accounts. → Mi Cloud and disable unnecessary options (e.g., gallery sync).
• 🔄 Check the Download folder - there can accumulate files from messengers and mail.

💡

If you use Google Photos for backup, turn on the “Free Space” option in the app settings, which will automatically delete local copies of photos that have already been uploaded to the cloud.

6. Viruses and Malware: Hidden Threats

Yes, even Redmi 9 can have viruses, often masquerading as harmless applications (like “memory cleaners” or “Internet speeders”) and downloading ads, mining cryptocurrency or stealing data in the background, such programs can take up to 1-2 GB of memory at the expense of:

• 📦 Downloading banner ads;
• 📊 Collecting logs of your activity;
• 🔄 Downloading updates for malware.

How to check your smartphone:

1. Install an antivirus (Malwarebytes or Dr.Web Light)
2. Check the list of installed apps for suspicious ones (such as those with names like “Super Cleaner” or “Fast Boost”).
3. Go to Settings → Battery → Battery → Battery Use and see which apps consume a lot of power in the background.

⚠️ Note: If you notice that your memory is filling up at night or when your phone is not in use, this is a sure sign of malware. Some viruses only activate when you connect to Wi-Fi to download data.

7. Misuse of the memory card

Many Redmi 9 users extend memory using microSD, but they do it wrong.

1. FAT32 formatting: This format does not support files larger than 4GB. If you download large games or videos, they are “cut off” and memory is clogged with snippets.
2. Install applications on SD: MIUI allows you to transfer apps to the card, but they run slower and create temporary files in the main memory.
3. No backup: If the card fails, the data will be lost and the system will continue to write files to internal memory.

How to set up the memory card correctly:

• 📱 Format it in exFAT or NTFS (PC).
• 🔧 In the storage settings (Settings) → Memory. → Map. SD) Select “Inner Memory” (but note that the card will not be used on other devices after that).
• 🎮 Don't put it on. SD high-demand games (PUBG, Call of Duty - they'll be laying.

💡

If you use a memory card as an internal one, check it regularly for errors through your PC (right click → Properties → Error Check).

FAQ: Frequent questions about memory on Xiaomi Redmi 9