wipe Galaxy S9 cache partition

How to update Galaxy S9 or S9 Plus to Android Pie (Android 9)?

As in January 2019, you can update Galaxy S9 or S9 Plus to Android Pie (Android 9) in most regions.

Of course, for carrier-locked phones, Android update always arrives slower than unlocked ones.

This Galaxy S9 Android Pie update guide explains why and how to update Galaxy S9 or S9+ to Android Pie, and answers some questions you may have on Android Pie update for Galaxy S9 and S9+.

Should I update Galaxy S9 or S9 Plus to Android Pie (Android 9)?

The short answer is yes, for most owners.

Once the update is available, you should update Galaxy S9 or S9 Plus to Android Pie for the following reasons:

Security. All future monthly security update/patch will be based on Android Pie. Samsung will not release Galaxy S9 and S9+ security patches for Android Oreo after Android Pie update is released in your region.
Performance. Android Pie address not only some security but also performance issues. Especially, Android Pie has improved a lot in battery management to extend the battery life (screen-on time, SOT) for Galaxy S9 and S9+. Of course, Android Pie cannot increase the battery capacity, or make the CPU run faster. But it does make the power consumption and CPU usage more efficient.
New Android Pie features. Besides the underhood improvements, Android Pie brought many useful new features for most users as explained in this page. For example, you can use the lockdown mode to temporally disable biometric unlock and smart lock. Or you can use the magnifier when selecting text.
New One UI features. Samsung changed the Samsung Experiences to One UI (FYI, it has nothing to do with Android One) in the Android Pie update. In addition to the visual (UI)changes, there are many functional updates as well. For example, you can try the navigation gestures on Galaxy S9 or S9+ (which is different from the navigation gestures in stock Android Pie). The night mode in Galaxy S9 and S9+ works better than the stock Android Pie dark theme (+night mode).

Of course, you cannot expect “stock” Android Pie in the Android Pie update for Galaxy S9 and S9+. As an Android manufacturer, Samsung has to customize the OS to differentiate itself from other manufacturers.

For a very small portion of owners of Galaxy S9 and S9+, you may have to withhold a while if:

You are using

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How to use Galaxy S9 safe mode on Galaxy S9 and S9+?

Galaxy S9 safe mode guide: what is Galaxy S9 safe mode? when you need it? how to enter Galaxy S9 safe mode? how to use it?

simon · Leave a Comment

You can use Galaxy S9 safe mode to identify possible causes of some problems or strange behaviours of Galaxy S9 and S9+.

This safe mode is safe for your data, settings and apps. They will not be affected or altered when using the safe mode on Galaxy S9 and S9+.

This Galaxy S9 how-to guide shows you when you may need Galaxy S9 safe mode, two ways to enter the safe mode for Galaxy S9 and S9+, and how to use and exit Galaxy S9 safe mode.

What is Galaxy S9 safe mode? And when do you need Galaxy S9 safe mode?

Like most other Android phones, Galaxy S9 and S9+ have a special Galaxy S9 safe mode letting you troubleshoot possible problems caused by third-party apps.

In Galaxy S9 safe mode, all third-party apps installed by you were temporally disabled so that you can determine whether the problem is caused by such apps.

Your data, settings, and app data are not affected when you reboot Galaxy S9 or S9+ into Galaxy S9 safe mode

Galaxy S9 safe mode can only determine whether some strange behaviours or problems are caused by third-party apps. It is not able to pinpoint the app.

Unlike Galaxy S9 recovery mode which is not part of Android OS, Galaxy S9 safe mode is a special mode of Android OS.

So, under the Galaxy S9 safe mode, you can still make and receive calls, connect to the Internet, use pre-installed apps. The safe mode only prevents you from using apps installed by you.

You need to try Galaxy S9 safe mode before you visit the service centre because technical support in most service centres does not solve issues due to third-party apps. They only diagnose problems in the firmware and pre-installed apps.

Although Galaxy safe mode does not change your data and settings, you may lose some home screen customizations after you exit the safe mode. So, you may still consider to back up Galaxy S9 before rebooting into the safe mode.

How to reboot into Galaxy S9 safe mode?

There are two ways to reboot into Galaxy S9 safe mode:

Use the power button options if Galaxy S9 or S9+ is currently powered on.
Use buttons if the phone is powered off.

Method 1: Use power button options to reboot into Galaxy S9 safe mode

If the phone is powered on, you can… Read the rest

How to reboot into Galaxy S9 recovery mode and to clear Galaxy S9 cache partition on Galaxy S9 and S9+?

simon · 8 Comments

You can use Galaxy S9 recovery mode to flash new ROMs, clear Galaxy S9 cache partition, and to check recovery logs.

Although Galaxy S9 recovery mode was designed for some advanced users, you may need some of the features, especially clearing the cache partition to fix some problems after a major update.

This Galaxy S9 guide explains to you the functions of Galaxy S9 recovery mode, the way to reboot Galaxy S9 or S9+ into recovery mode, usage of the recovery mode, and methods of clearing Galaxy S9 cache partition.

What is Galaxy S9 recovery mode?

All Android phones have a special mode: recovery mode, which allows you to fix any Android problems and perform some actions (for example, patch the system) to the Android system without loading Android OS.

In the phone storage layout, there is a special partition for recovery. This partition is protected from Android OS and other partitions.

Galaxy S9 is not an exception.

If you think you never used Galaxy S9 recovery mode, you are very likely wrong.

When you install updates (including monthly security updates) for Galaxy S9 and S9+, you may notice the phone will reboot twice automatically.

During this updating process, Galaxy S9 or S9+ would reboot into Galaxy S9 recovery mode first to apply the update, then reboot into Android OS so that you can use Galaxy S9 and S9+.

Of course, Galaxy S9 recovery mode offers more functions including:

To apply Android OS update
To reset (factory data reset) Galaxy S9 or S9+.
To wipe/clear Galaxy S9 cache partition.
To boot into bootloader (download mode).
To flash official or third-party ROMs for Galaxy S9 and S9+.
To mount /system partition manually.
To check recovery logs.
To run a graphics test.

Although Galaxy S9 recovery mode is seldom used for most Galaxy S9 and S9+ owners, you may need to reboot into Galaxy S9 recovery mode to fix some problem with your S9 or S9+.

In fact, most Galaxy S9 and S9+ owners reboot the phone into Galaxy S9 recovery mode to clear the cache partition to fix some issues after a major Android update.

You should not confuse Galaxy S9 recovery mode with Galaxy S9 safe mode, which is a special mode of Android OS.

How to reboot into Galaxy S9 recovery mode?

The key combination to reboot into Galaxy S9 recovery mode is Bixby button+ … Read the rest