Android 9.0 might bring us the feature that we’ve all been asking for! Adoptable storage gives users the ability to have their devices treat their internal and external storages as one. This interesting Note 9 Pie firmware was discovered in an XDA Developers forum for Note Pie Updates. However, the feature was not fully optimized yet as it crashes past 40%.
Adoptable storage gives you the option to either use your external storage as an adoptable storage, or to simply use it as basic file storage. Android supports external storage, but these were usually limited to simple file storage due to their expected impermanence.
Storage devices also have minimal data protection: when adopted, the external storage is formatted and encrypted (with a randomly generated encryption key) to work with only a single Android device at a time. It’s advisable to consider adoption of storage only if the external storage slot location is stable, like inside the battery compartment or behind a protective cover.
Android first introduced their first adoptable storage in the Android 6.0 marshmallow release, but was no longer supported in later Android releases until Pie. The adoptable storage feature may not be stable for now, but it may be ready when the beta versions come or the final version of Android Pie rolls out.