Memory Cleanup on Xiaomi Redmi 9: A Complete Guide with Hidden Chips MIUI

Xiaomi Redmi 9 is one of the most popular budget smartphones, but even its 64 or 128GB of memory is eventually clogged with unnecessary files. Slowdowns, lags when opening apps and sudden notifications of space shortages are familiar stories? In this article, we will discuss all possible ways to clean up memory, including little-known functions. MIUI, which work without root rights.

It's important to understand that the problem is not just the amount of free space, but the fragmentation of data. 10-15 GB free, the phone can slow down because of how the system distributes files from memory. MIUI Clean the cache of system applications (this is often missed in standard instructions) and which files can be safely deleted without risking the operation of the phone.

This article is suitable for all Redmi modifications. 9: Redmi 9A, Redmi 9C, Redmi 9T redmi 9 Most of the methods are relevant for other Xiaomi smartphones based on the MIUI 12/13/14, But with the specifics of this particular model, like working with a partition. /data/app on a MediaTek Helio processor G80/G35.

1. Built-in tools MIUI: What's really working?

Let’s start with the obvious – standard cleaning functions in the MIUI. Many users limit themselves to clicking the "Clean" button on the memory menu, but that only removes the tip of the iceberg, and let's see which tools are really effective and which ones can be skipped.

Main path: Settings → The phone. → Memory. Here you'll see a diagram of occupied space and a clear button. But here's a caveat: the default system only shows user data, hiding system debris. To see the full picture, click on the three dots in the top right corner and select "Deep Cleanup".

• 📱 Quick Cleanup: Deletes app cache and temporary files.Secure, but frees everything 1-3 GB.
• 🗑️ Deep Cleanup: Analyzes duplicates, large files and unused files APK. Maybe I can find it. 5-7 GB of garbage.
• 🔍 Manual mode: allows you to choose which files to delete (for example, leave the cache of messengers, but clean games).

Pay special attention to the "Recommendations" section. MIUI It suggests removing rarely used apps or transferring files to a memory card, but not all tips are helpful: for example, the system may recommend removing the cache of Google Play Services, which will lead to problems with app updates.

⚠️ Warning: Do not cache system applications like com.android.systemui or com.miui.home through standard settings. MIUI (Disappearance of icons, errors when unlocking. Use the methods in section 4 to clean them.

2. Cleaning the cache of applications: what can be deleted and what can not

The app cache is the main memory eater on Redmi 9, and it takes 3 to 10 GB on average, but it can't be safely deleted, like the Telegram cache or WhatsApp cache, which contains media files that you'll have to download again when you delete it, and the game cache is like, PUBG Mobile or Genshin Impact can weigh a few gigabytes, but cleaning it will lead to a long boot on the next launch.

How to clean the cache correctly:

1. Go to Settings → Applications → Application Management.
2. Sort apps by cache size (click on three dots) → "Sorting → By cache size").
3. Select the app and click "Clear Cache." Don't click "Clear Data" - it will delete all settings and accounts!

Especially a lot of garbage accumulates:

• 🎮 Free Fire, Call of Duty Mobile, Honor of Kings (cash to video) 2-4 GB).
• 📷 Social networks: TikTok, Instagram, Facebook (cache to) 1-2 GB).
• 🌍 Maps: Google Maps, Yandex.Maps (offline card cache can weigh up to 500 MB).
• 📺 Streaming services: YouTube, Netflix (video cache up to 1 GB).

⚠️ Warning: If the app starts to slow down after cleaning the cache (for example, Facebook or Facebook) VK), It means it's actively using the cache to speed things up. 200-300 MB cache for this application.

Remove the cache of games you don’t use|Clean the cache of social networks (except messengers)|Check the size of the cache of maps and navigators|Delete the cache of streaming services (if you watch online, not download)

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3. manually removing unnecessary files: where to look for garbage

Even after cleaning the cache, Redmi 9 still has a lot of unnecessary files that the system doesn't delete automatically, and can be found manually through a conductor (standard or Mi File Manager).

Pay special attention to the folder /Android/data. This is where the application data is stored, and many of it can be deleted without consequences:

• 🗃️ Remote application folders (e.g. com.tencent.ig) are PUBG Mobile, if you have uninstalled it).
• 🎵 Folders of music services (com.spotify.music, en.yandex.music) if you do not download music offline.
• 📦 Cloud storage folders (com.dropbox.android, com.google.android.apps.docs) if you don't use offline access.

How to securely delete files:

1. Open Mi File Manager (or any other root-enabled explorer, if any).
2. Go to /storage/emulated/0.
3. Select unnecessary files and click "Delete".
4. If you see a warning about system files, do not delete them!

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Before you manually delete files, back up important data. For example, copy a folder. DCIM/Camera It's going to take a computer or a cloud. 5 It will save your photos in case of accidental deletion.

4. Hidden functions MIUI memory-cleaning

MIUI It hides a few useful tools that you can't see in the standard menu, and you can activate them through developer mode or special combinations.

The most effective method is to clean the Dalvik cache, which is a system cache that MIUI It does not touch during standard cleaning, but it can take up to 1-2 GB to remove it:

1. Activate Developer Mode: Go to Settings → About Phone and click on MIUI Version 7 times.
2. Back to Settings → Additionally. → For developers.
3. Find the option “Clear Dalvik cache” and confirm the action.

Another hidden feature is optimizing memory through an engineering menu, which only works on MediaTek processors (like Redmi 9):

1. Open the Phone app and enter the code ##4636##.
2. Select "Battery Information" (yes, it's weird, but it works).
3. Click on the three dots in the upper right corner and select "Memory Optimization".
4. Wait until the process is completed (it can take 5-10 minutes).

Also in MIUI There is a hidden partition to clean system logs that take hundreds of megabytes:

• 📜 Logs of error: /data/log (Root rights are required for access).
• 📡 Logs of the network: /data/misc/net (can be cleaned through ADB).
• 🔄 Logs of updates: /cache/recovery (Remove it if you are not planning to roll back the firmware).

⚠️ Note: Do not delete files in folders /system or /vendor — Even with root rights, be careful: deleting the wrong files can disrupt the camera, network or sensors.

5. Data transfer to memory card: how to do it correctly

Redmi 9 supports memory cards up to 512 GB, but many users face a problem: the system does not allow you to transfer all applications to the memory card. SD. Even if you put a map in, MIUI The default is to use it only for media files. How to get around this restriction?

Method 1: Formatting a card as internal memory (recommended for class cards) A1/A2):

1. Put the memory card in.
2. Go to Settings → Storage → SD card.
3. Select "Settings" (three dots) → "Storage settings" → "Formatting as an internal".
4. Note: After that, the map will not be read on other devices without formatting!
5. After formatting, select “Move Data Now”.

Method 2: Manual transfer of applications (without map formatting):

1. Go to Settings → Applications → Application Management.
2. Select the application you want to transfer.
3. Click on "Storage" → "Change" → select the SD card.
4. Confirm the transfer. Not all applications support this feature!

What applications can not be transferred to the map:

• 🔒 Widgets (will stop working).
• 📱 System applications (MIUI Launcher, Settings, etc.).
• 🎮 Games with high demands (Genshin Impact, Call of Duty Mobile).
• 🔐 Annexes with DRM-Protection (Netflix, Disney)+).

How to speed up the memory card:

• Use class cards A2 (For example, SanDisk Extreme A2 Samsung EVO Plus A2).
• Format the card in exFAT (if you use it as a removable drive) or EXT4 (if only an internal memory).
• Don’t fill up more than 80% of the card, which reduces the speed of the recording.

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Formatting the card as internal memory increases the speed of applications on the 20-30%, But it's tied to this phone, and if you change devices a lot, you better use the card as a removable drive and only transfer media files.

6. Cleaning through ADB: for advanced users

If standard methods do not help, you can use them. ADB (Android Debug Bridge is a debugging tool that allows you to delete files that are not available through a regular interface. This method requires a computer and a little technical skills, but can free up the computer. 2-3 GB of additional space.

What you need:

• 🖥️ Computer with Windows/Linux/macOS.
• 🔌 Cable USB (preferably original).
• 📥 Installed drivers ADB Fastboot (you can download from the Android Developers website).
• 📱 Initiated debugging mode USB phone-on.

Step-by-step:

1. Put the debugging on. USB: Settings → The phone. → Version. MIUI (7 times) → Settings → Additionally. → For developers → Debugging by USB.
2. Connect your phone to your computer and confirm your trust in the device.
3. Open the command prompt (or Terminal on macOS/Linux) and type:

adb devices

Make sure your Redmi 9 is on the list.

Now you can delete unnecessary files, for example, to clear the cache of all applications:

adb shell pm trim-caches 1000000000

This command removes cache that exceeds 1 GB (value in bytes).

To delete temporary update files:

adb shell rm -rf /data/local/tmp/*


adb shell rm -rf /cache/*

To clean the logs:

adb shell rm -rf /data/log/*


adb shell rm -rf /data/tombstones/*

⚠️ Note: Do not follow the commands adb shell rm -rf /data/ or adb shell rm -rf /system/ — It will erase all data completely or make your phone blink.

If you are not sure about your actions, use a more secure method – viewing large files through the Internet. ADB:

adb shell du -ah /data | sort -rh | head -n 20

This team will show 20 Largest files and folders in the section /data. This way you can see exactly what is taking up space and make a decision to remove it.

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Before work, ADB Create a full backup through adb backup or Mi Cloud. -apk -obb -shared -all -f backup.ab. This will save all applications, their data and media files in one archive.

7. Alternative methods: from reset to cloud services

If none of these methods worked, and the memory is still clogged, there are radical or alternative methods, and let's look at the pros and cons.

1.Reset to factory settings

• ✅ Frees up all memory, returning the phone to the “out of the box” state".
• ❌ Deletes all data, including photos, messages and apps.
• ⚠️ After a reset, Redmi 9 may run faster, but the first day will be re-indexed files, which can cause lags.

How to reset:

1. Create a backup (via Mi Cloud or computer).
2. Go to Settings → About the phone → Reset settings.
3. Select "Erase all data" and confirm.

2. Use of cloud services

If the problem isn't space shortage but file fragmentation, moving some of the data to the cloud can help.The best options for Redmi 9 are:

• 🌥️ Google Photos: Automatically uploads photos and videos in original quality (up to 15 GB free).
• ☁️ Mi Cloud: 5GB free, but synced only with your Xiaomi account.
• 📁 Dropbox or Mega: Easy for documents and backups.

Installation of custom firmware

This is an extreme method, but some custom firmware (like LineageOS or Pixel Experience) is better optimized than standard firmware. MIUI. They take up less space and don't clog up memory with unnecessary system applications:

• ⚠️ Requires unlocking the bootloader, which resets all data.
• ⚠️ It may disrupt some functions, for example, IR-blaster NFC firmware).
• ✅ Releases until 3-5 GB by removing the Blaatware (Xiaomi preinstalles many unnecessary applications).

4. Connecting an external drive over OTG

If you need to temporarily free up space (for example, to update firmware), you can connect a flash drive or external hard drive through the OTG-adapter. Redmi 9 supports USB OTG, So you can:

• Transfer photos and videos to the flash drive.
• Install applications directly to the external drive (via ADB).
• Use the flash drive as temporary storage for large files.

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Resetting to factory settings is not just a memory cleanup, it's a complete reboot. 9 It will work faster, but the first 1-2 Days are possible to slow down due to background optimization MIUI. Don’t reset before important events (such as a trip) when your phone should be running smoothly.

FAQ: Answers to Frequent Questions