You open a gallery on Xiaomi, and your smartphone insists, "Memory is full," even though there are dozens of photos and apps at a minimum. Or worse, the phone starts to slow down, apps fly out, and the storage settings show a red bar "98% occupied," even though you haven't downloaded anything.
This problem is typical of Xiaomi, Redmi and POCO devices — especially on budget models with 32-64 GB of memory, not only user files, but also hidden system data, application cache, F2FS/ext4 file system errors, and the “features” of MIUI firmware. In this article, we will analyze all possible causes, from banal garbage to hardware failures — and give step-by-step instructions how to free up space without losing data.
Spoiler: 80 percent of the time, the problem is solved without a factory reset. But if you've tried to clean the cache through Settings → Storage and it didn't work, read on. We've put together 7 proven methods, including little-known tricks with ADB and manually cleaning /data folders.
1.Cash and junk files: why they eat gigabytes
The first thing that comes to mind when you say "Memory is full" is to clear the cache, but in MIUI, it's a nuanced process, because it creates hidden backups for applications (com.miui.backup folder), temporary update files (Download), and even duplicate media files in the MIUI folder.
How to check how much space is taken up by garbage:
- 📱 Open the Settings. → Storage and tap on the "Other Files" section, which often hides up to 5-10 GB of unnecessary data.
- 🗑️ Use the built-in storage analyzer (in new versions) MIUI It's called Cleanup. It's going to show you which apps are taking up the most space.
- 🔍 Install a third-party analyzer, such as Files by Google or SD Maid – Find files that the standard manager doesn’t see.
Important: Do not clear the cache of system applications (e.g. com.android.systemui) through recovery or ADB — This can cause your phone to reboot cyclically. Use only built-in tools for safe cleaning. MIUI.
2. Hidden folders and system duplicates: where to look
One of the most insidious memory eaters in Xiaomi is hidden folders that don’t show up in the standard file manager.
- 📁 /storage/emulated/0/MIUI/ — here are stored backup copies of themes, wallpapers and settings (may weigh up to 1–2 GB).
- 📁 /data/data/com.miui.gallery/ — cache of the gallery, including thumbnails and temporary edit files.
- 📁 /storage/emulated/0/Android/obb/ — Game files (sometimes left after deleting applications).
- 📁 /storage/emulated/0/Download/uninstall/ — lie APK-remote-app files.
How to find and remove them:
- Connect your phone to your PC and enable File Transfer (MTP) mode.
- In Windows Explorer (or Finder on Mac), enable the display of hidden files (View → Hidden Items).
- Delete the contents of the folders listed above, except Android/data (game saves are stored here).
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If the folder is not deleted, check if it is being used by some process. Reboot the phone and try again.
Careful: Do not delete DCIM, Pictures or WhatsApp folders, which may contain important data, and do not touch files with the.nomedia extension, which are necessary for the gallery to work properly.
3. File system errors: how to fix without resetting
If the memory still shows 100% fullness after cleaning the cache and removing the garbage, the problem may be that the file system is damaged.
- ⚡ Unexpected power outage during file recording.
- 🔄 Interrupted update MIUI.
- 📱 Connecting the phone to "curved" charges or USB-hub.
How to check and correct:
- Reset the phone to Recovery mode: Turn off the device, then press Volume up + Power.
- Select Wipe & Reset → Wipe Cache (not to be confused with Wipe Data – it’s a reset!).
- After restart, check the storage. If the problem persists, run the command via ADB: adb shell fsck /dev/block/bootdevice/by-name/userdata
What if the fsck doesn’t work?
Attention: if after this manipulation the phone stopped loading, most likely the partition table is damaged, in which case only the flashing through Fastboot will help.
MIUI's "Optimization": Why the System Reserves Memory
MIUI has an unpleasant feature: it reserves up to 3-5 GB of memory for “system needs”, even if the phone has almost no files.
- 📦 Backup storage for updates (folder) /cache).
- 🔄 Logs of the system (/data/log), which can grow to a gigabyte.
- 🛡️ Secure application data (such as Mi Cloud or Google Drive).
How to reduce the reserved memory:
- Turn off automatic MIUI update in Settings → About Phone → System Update.
- Clean Logs with ADB: adb shell su -c "rm -rf /data/log/*"
- Turn off backup in Mi Cloud (Settings → Xiaomi Account → Mi Cloud → Backup).
Disable autoupdate MIUI|Delete logs via ADB|Elean /cache in recovery|Deactivate backup in Mi Cloud|Check Download folder for old APK-->
Critical information: If logs reappear in large volume after cleaning, it is a sign of malware or a logd service failure, in which case only a reset or firmware will help.
5. Malware and “left-wing” applications
Viruses and ad modules often disguise themselves as system processes and create hidden files in /data or /system folders. For example, the Android.Triada Trojan can replace the system's libraries, causing memory to leak unnoticed.
Signs of infection:
- 📈 Memory fills up on its own, even if you don’t install anything.
- 🔋 The phone is warming and discharged quickly.
- 📱 Unknown applications appear in Settings → Annexes.
How to check and delete:
- Install Malwarebytes or Dr.Web Light and scan the system.
- Check the list of installed applications: look for suspicious names like com.system.update or android.service.secure.
- If the antivirus does not find anything, but the memory still leaks, reset through Settings → Additional → Restore and reset.
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If the problem comes back after the reset, the virus is in the firmware, in which case only a complete flashing through the Mi Flash Tool will help.
6. Hardware problems: when the drive is to blame
If all software methods have been tried, but the memory still shows 100% fullness, the problem may be the physical wear of flash memory. Cheap Xiaomi models (such as the Redmi 5A or Redmi 7) often come with low-quality eMMC drives that fail after 2-3 years.
Signs of hardware failure:
| Symptoms. | Probable cause | Decision |
|---|---|---|
| Memory shows different volume in Settings and TWRP. | Damage to the partition table. | Re-markup via Fastboot. |
| The phone “forgets” files after rebooting. | Wear of eMMC cells. | Replace the drive. |
| The recording speed drops to 1-2 MB / s. | Degradation of the memory controller. | Replacement of motherboard. |
How to diagnose:
- Connect your phone to your PC and run the test via CrystalDiskMark or H2testw.
- If the read/write speed is below 10 MB/s, the drive is worn out.
- Check it out. SMART-status ADB: adb shell dumpsys diskstats Look for lines with bad blocks errors.
Warning: If tests show critical wear, don't use your phone to store important data -- it can fail at any time.
7.Memory card: why it might be to blame
If you use microSD as internal memory (the Adoptable Storage feature in MIUI), the problem may be that Xiaomi often formats cards incorrectly, which is why:
- 📊 The memory of the card is “merged” with the internal, but the system does not see it.
- 🔄 Files are duplicated on both drives.
- 🚫 The card may be damaged, but the phone doesn't tell you.
How to check:
- Go to Settings → Storage and see how much space “External memory” takes up.
- If the card is displayed as “damaged”, format it via a PC (FAT32 or exFAT file system).
- Turn off Adoptable Storage in Settings → Additional → Storage.
Importantly, if the card was used as internal memory, some of the applications may stop working once they're removed, and then you'll have to reinstall them.