Note : When you adopt your SD card as internal storage, you can’t remove the SD card from the device without affecting the functionality of your device and the SD card is not usable in any other device, including your PC. The SD card is formatted as a local EXT4 drive, encrypted using 128-bit AES encryption and mounted as part of the system. Once your adopt an SD card on a Marshmallow device, it will work only with the device.
Make sure you’re using a speedy SD card (Class 10 and UHS), because if the SD card is less expensive, slower SD card, it will show down your apps and device. You cannot move pre-installed apps to adopted SD card in this way. Here is a step by step guide to install and move apps in Android 6.0 Marshmallow.
#1. Insert the SD card in your device, you’ll see a notification saying that a new SD card was detected and Tap on “Set Up”.
Note : If you don’t see this notification, open Android Settings app, go to “Storage & USB”, and click the menu button to “Format as Internal”.
#2. A prompted display allowing you to choose whether you want to set up the SD card as portable storage or internal storage. Tap on “Use as internal storage” and the click “Next”.
#3. A message display warning you that after the SD card is formatted as internal storage, it will only work in this device. You also advised to back up the data on the card. Once you’re ready to continue adopting the SD card as internal storage, tap on “Erase & Format”.
#4. If there are still apps installed on the SD card that you forgot to move back to the internal storage, the device displays a warning message that the apps will be erased. To see which apps are still installed on the SD card, tap on “See Apps”. If it doesn’t matter to you that the apps will be erased, click on “Erase Anyway”.
#5. Now Android will format and encrypt your SD card. Once the formatting process is done, you’ll be asked if you want to move data currently on the device’s internal storage to SD card. This step will move your photos, files and some apps to the SD card. To migrate the data to SD card now, click on “Move now”. If you don’t want to move your data yet, tap on “Move Later”, the internal storage remains the preferred storage for all content.
Note : If you choose “Move Later”, you can migrate the data later by going to Settings > Storage & USB. Click on the SD card drive, the tap the menu button and select “Migrate data”.
#6. When the process is finished, a message displays showing that your SD card is working and click on “Done”.