Xiaomi magazine buffer: purpose, setting and optimal size

If you've ever looked at a developer's settings on a Xiaomi smartphone, you've probably noticed a mysterious item called "Log Buffer Size." Many MIUI users don't understand why it's needed, how it affects the system, and how much to set up to keep the device running, meanwhile, incorrect buffer settings can lead to the loss of important debugging logs when crashes or, conversely, to overloading memory with unnecessary data.

In this article, we will take a closer look at what a magazine buffer is in MIUI firmware, how it relates to Android, what values are considered optimal for different Xiaomi/Redmi/POCO models, and give you a step-by-step setup instruction, and you will learn how to manually clean the buffer and why its size can spontaneously reset after updates.

What is a magazine buffer on Xiaomi and why you need it?

Log buffer is a special area in the smartphone's RAM where system logs are temporarily stored.

• 🔹 Application errors (coloring, hanging, FC — Force Close)
• 🔹 System events (services start/stop, network status changes)
• 🔹 Android core (processor, memory, drivers)
• 🔹 Debugging (data for developers via adb logcat)

By default, the magazine buffer on Xiaomi is fixed in size — usually 256 KB or 1 MB, depending on the version of MIUI. When the buffer is filled, new entries overwrite old, erasing potentially important information. For example, if the smartphone suddenly rebooted and the buffer was small, the error logs may not persist, and it will become impossible to find out the cause of the failure.

For ordinary users, the journal buffer is not practical - it is needed mainly:

• 🛠️ Developers (for debugging applications)
• 🔧 Service center engineers (for hardware problems diagnosis)
• 🤖 Enthusiasts of custom firmware (when searching for bugs in unofficial assemblies)

⚠️ Attention: Increasing the magazine buffer won't speed up the smartphone or solve lag problems.It's a diagnostic tool, not an optimization tool.

Where is the magazine buffer setup in MIUI

To change the buffer size, you first need to activate the developer mode.

1. Go to Settings. → The phone.
2. Click 7 times in a row on the MIUI version (you will be notified “You became a developer”).
3. Go back to the main settings menu and open a new section for developers.

Inside the developer menu, find the item: Logger buffer sizes, which can be called by different names depending on the version of MIUI:

• Kernel Log Buffer (Kernel Log Buffer)
• System log buffer size (System log buffer size)
• Log settings (log settings)

If you don’t have a clause, your firmware version doesn’t support manual buffering, as is the case with some low-end Redmi models (like the Redmi 9A or Redmi 10A) where the manufacturer has limited functionality.

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Some firmware has a hidden item. Try searching for "log buffer" or "log buffer" in your settings.

Optimal magazine buffer size for Xiaomi in 2026

There is no universal value that would fit all devices. The optimal size depends on:

• 📱 Smartphone models (volume of RAM)
• 🔄 Failure rates (if errors occur frequently, a large buffer is needed)
• 🛠️ Purposes of use (application debugging vs. system diagnostics)

Below is a table of recommended values for different scenarios:

For most users, a 4MB value is enough to save the logs of the last 10-15 minutes of the system. If you are not engaged in development, it makes no sense to put more than 8 MB: the buffer will take up RAM, which could go to background tasks.

⚠️ Note: On devices with 4GB of RAM or less (e.g. Redmi) 9C, POCO M3) It is not recommended to put a buffer greater than 2 MB – this can lead to slowing down of the interface due to lack of memory.

How to change the size of the magazine buffer: step-by-step instructions

The setup procedure is the same for all Xiaomi/Redmi/POCO devices with unlocked developer mode.

Activate the Developer Mode|Open Settings → For developers|Find the item "Size of the magazine buffer»|Select the desired value from the list|Reboot your smartphone-->

Step 1. Open the Settings. → For developers.

Step 2. Scroll down to the Debugging or Journals block (name depends on the MIUI version).

Step 3. Find the magazine buffer size and tap it.

Step 4. In the window that appears, select one of the values proposed (usually 256 KB, 1 MB, 4 MB, 8 MB, 16 MB). If the desired size is not available, see the next section on manual input.

Step 5: Reboot the device to make the changes effective.

Once rebooted, the new buffer size will be active, and you can check it through the adb command:

adb shell getprop | grep logbuffer

How to set the size of the buffer (if there is no necessary value)

On some firmware (e.g. MIUI 14 for Xiaomi 13T), the list of predefined values is limited. To set an arbitrary size, you will need to:

1. Install ADB on your computer (instructions below in FAQ).
2. Connect the smartphone to the PC and allow debugging over USB.
3. Execute the command: adb shell setprop logbuffer.size 4M (where 4M is the desired size in megabytes).
4. Reset the device.

Values allowed for manual input:

• 256K, 512K, 1M (for memory savings)
• 2M, 4M (optimal for diagnosis)
• 8M, 16M, 32M (Developers Only)

⚠️ Attention: After update MIUI through OTA Custom buffer settings will reset to default values. To avoid this, use the Magisk LogBuffer Size Changer module (available on the forum) XDA Developers).

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Changing the buffer size through ADB is a temporary solution, requiring system files to be edited for permanent effect, which could disrupt the warranty.

How to clean the magazine buffer manually

If the buffer is full of unnecessary logs (for example, after debugging), it can be cleaned without rebooting.

Method 1. Through ADB:

adb shell logcat -c

This command will reset all logs, including kernel, system, and main.

Method 2. Through the application:

• Install Logcat Reader or MatLog from Google Play.
• Open the app and click Clear Logs.
• Confirm the cleanup.

Method 3: Reboot:

A simple smartphone rebate automatically clears the log buffer, but this method is not suitable if you need to save logs before rebooting (for example, to analyze the cause of the crash).

Frequent problems and their solutions

When working with the magazine buffer, Xiaomi users face typical errors:

Problem 1: Buffer settings are reset after the MIUI update.

Solution: Use the Magisk module to capture values or set up an automatic script through Tasker, which will apply the desired size after each reboot.

Problem 2: The buffer does not save logs after the reboot.

Solution: Logs in the buffer are stored only in RAM. To save them permanently, use the command:

adb shell logcat -d > /sdcard/logcat.txt

This exports the current logs to the file on the internal drive.

Problem 3: The smartphone slows down after the buffer increases.

Solution: Return the value to 1-2 MB and check the free RAM in Settings → Memory. If the lags are left, reset the cache through Recovery.

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If the smartphone starts to overheat after changing the buffer, check the background processes through Settings → Battery → Battery Use. Perhaps some application actively writes in logs.

FAQ: Answers to Frequent Questions