Modern smartphones require more and more space to install applications, save high-resolution photos and messenger caches. Built-in storage is often insufficient, and models with more memory cost significantly more. In this situation, a microSD memory card comes to the rescue, which can be turned into a full-fledged extension of the system drive.
In this material we will analyze in detail the process of activating the function Adoptable Storage, available in many versions of the operating system. You will learn how to properly prepare a drive, what risks exist when formatting, and why not all cards are suitable for this task. The instructions will help you free up valuable gigabytes of built-in storage without losing device performance.
What is Adoptable Storage and how it works
Starting with the sixth version of the operating system Android 6.0 Marshmallow, Google has introduced technology that allows you to integrate an external drive directly into the device’s file system. This function is called Adoptable Storage. Unlike the traditional mode of operation, when the card is used only for media files, in the new mode it becomes an extension of the internal memory.
When this mode is activated, the system encrypts the external drive with a unique key tied to a specific smartphone. This means you can't simply remove the card and insert it into a computer or other phone to read the data. Encryption Keeps your data safe, but makes the card unusable on other devices without full formatting.
It is important to understand the difference between Portable Storage and Internal Memory modes. In the first case, the card works as a flash drive for photos and music. In the second, the system can install applications on it and store system data. However, the quality of work directly depends on the read and write speed of the drive itself.
⚠️ Attention: After formatting the card in internal memory mode, all data on it will be permanently deleted. Be sure to back up important files before starting the procedure.
Use UHS-I or UHS-II class memory cards with high write speeds. Slow cards can cause noticeable slowdowns in the operation of the interface and applications.
Memory card requirements and device compatibility
Not every microSD card is suitable for expanding internal memory. For comfortable operation of the system, you need a drive with high random read and write speeds. Smartphone manufacturers often recommend using cards of class Class 10 or higher, as well as models labeled A1 or A2optimized for working with applications.
Many smartphone manufacturers, such as Samsung, Huawei and Xiaomican programmatically restrict the ability to use this function in their shells. Even if the device is running the correct version of Android, the menu item may be missing. In such cases, users are forced to resort to third-party activation methods via a computer.
The capacity of the card also matters. It is recommended to choose a drive with a capacity of at least 32 GB, and preferably 64 GB or 128 GB. Using a card that is too small can quickly fill it up, which will negatively impact the performance of the entire device. The system perceives the combined space as a single whole.
| Characteristics | Minimum requirement | Recommended value | Impact on operation |
|---|---|---|---|
| Speed class | Class 10 | U3 / V30 | Speed of loading applications and saving photos |
| Application type | Class A1 | Class A2 | Performance of installed apps |
| Memory capacity | 16 GB | 64 GB and above | Number of available applications and files |
| Interface | UHS-I | UHS-II | Maximum bus bandwidth |
Preparing for formatting and backup
Before you start changing the storage type, you need to perform a number of preparatory steps. The most important step is to save all the valuable data currently on the card. The formatting process will destroy all information, and it will be impossible to restore it using standard means due to changes in the file system and encryption keys.
Connect the card to the computer via a card reader or use file transfer mode (MTP) when connecting the smartphone with a cable. Copy photos, videos and documents to your computer's hard drive or cloud storage. Make sure that the copy is created successfully and the files open.
It is also worth checking the status of the smartphone battery. The process of formatting and migrating data can take from several minutes to an hour depending on the size of the card. Battery drain at a critical moment can lead to file system corruption and data loss.
⚠️ Attention: Make sure the battery charge is at least 50-60%, or connect the device to a charger throughout the entire setup procedure.
☑️ Preparing for formatting
Standard activation method through Android settings
If your smartphone supports the memory expansion function at the software level, the setup process will take only a few minutes. You don't need to connect to a computer or use complex commands. Just go to the corresponding section of the settings menu.
Go to the menu Settings and find the section Storage or Memory. Select your microSD card from the list of connected storage devices. Usually, in the upper right corner of the screen or in the menu (three dots), the option to change the storage type is available.
Click on the item Storage settings or Format as internal memory. The system will warn you that the card will be formatted and encrypted. Confirm the action. After the process is completed, the system may offer to transfer existing data (photos, media) to a new drive.
Settings → Storage → SD card → Menu → Storage settings → Format as internalAfter successful completion of the operation, the card will be displayed as part of the internal memory. The total amount of available space will increase by the size of the card minus system overhead. Now you can install applications directly on the external drive.
After formatting, the card becomes an integral part of the system. Removing it without first disabling it in the settings may lead to malfunctions of applications installed on it.
Activation via ADB for devices without official support
Many manufacturers hide the ability to use the card as internal memory in their firmware, despite the presence of technical support in the Android kernel. For such cases, there is an activation method through USB debugging and a computer utility ADB (Android Debug Bridge).
First, you need to enable developer mode on your smartphone. Go to Settings → About phone and quickly click 7 times on the item Build number. After this, a new section will appear in the settings menu For developers. Enable the option USB debugging.
Connect your smartphone to the computer with a cable. The platform must be installed on the computer Android SDK Platform-Tools. Open a command prompt or terminal in the ADB tools folder and enter the command to test the connection:
adb devicesThe phone screen will ask you to allow debugging from this computer. Confirm it. Next, you need to find out the ID of your memory card. Enter the command:
adb shell sm list-disksIn response you will receive a disk identifier, for example, disk:179,64. Remember or copy this value. It will be needed for the next command, which will start the process of formatting and creating partitions.
Command to create a single partition
To fully use the card, enter the command: adb shell sm partition disk:XXX,XX private. Where XXX,XX is your disk ID. This will create one private partition.
Transferring applications and data management
After the card has become internal memory, the system does not always automatically transfer all applications to the new drive. You may need to manually manage app placement. This allows you to optimize performance, leaving the most important applications on the fast built-in chip.
Go to Settings → Applications. Select the desired app from the list. If the application supports transfer, the button Change will be active. Click on it and select SD card. The system will move the application files and its data to the external drive.
Not all applications can be transferred. Developers may prohibit the installation of their apps on external media for security or stability reasons. In this case, the transfer button will be inactive, and the application will remain in the built-in memory.
It is also worth considering that widgets and some system functions may not work correctly if the application is located on removable media that was accidentally removed or damaged. It is better to leave critical services on the main drive.
⚠️ Attention: When you reset your smartphone to factory settings, data on a card formatted as internal memory will also be deleted or become unreadable due to changing encryption keys.
Regularly check the health of the memory card using special utilities, for example, SD Insight. This will help you replace the drive in time before it fails.
Returning the card to portable storage mode
If you decide not to use the card as internal memory, you need to format it back to portable mode. This procedure will also delete all data, so be sure to transfer applications and files back to the built-in memory or to your computer.
In the menu Storage select your card and find the option Format as portable storage or Change storage type. The system will warn you about the need to transfer data. Follow the instructions on the screen.
Once the process is complete, the card will be available for use in other devices, cameras or computers without the need for additional formatting. However, all applications previously installed on it will stop working and will require reinstallation.
Can one card be used on different phones?
No, if the card is formatted as internal memory. It is encrypted with the key of a specific device. To use it on another phone, you will have to format it, which will delete all data.
Why does the phone slow down after expanding the memory?
Most likely, a slow memory card is used. The random block reading speed of cheap cards is low, which causes delays when launching applications and system operation.
What to do if the “Format as internal” option is missing?
The manufacturer of your smartphone has disabled this function programmatically. Try activating it through the ADB commands described in the section above, but this requires a computer.
Does this reduce the service life of the memory card?
Yes, intensive data recording by system processes and applications leads to faster wear of memory cells compared to conventional storage of photos and videos.
Is it possible to remove the card without formatting?
Technically it is possible, but the system will lose access to the data on it. For safe removal, always use the "Unmount" or "Eject" command in the storage settings before physically removing.