Samsung devices don't support Adoptable Storage. However, there is a workaround with ADB (root not required). Here are the commands for ADB:
adb shell
sm list-disks
sm partition <DISK> private
reboot
Notes:
<DISK>
needs to be replaced with the output of the previous command. For examplesm partition disk:179,64 private
.- If you don't want to convert the whole disk, then use this command instead:
sm partition <DISK> mixed <VALUE>
, where is the percentage (0-100) to keep as external storage. For examplesm partition disk:179,64 mixed 50
for 50%.- Reboot is optional, but recommend, so all apps detect the external storage.
If you have root access, you can use my app [Root Essentials][1] instead. It can do all of this automatically without a PC or terminal commands.