Hi Paul. Iv'e spent the better part of a couple of days setting up/troubleshooting adoptable storage on a GS7, using your excellent instructions, but seem to have hit a roadblock that is either a problem with my microSD card, or (more likely?), a problem with Samsung's implementation of the underlying code, and perhaps the reason they have chosen to hide adoptable storage. Would you please look at my post under your article, and share any thoughts/suggestions?
**Update** I spoke to soon about my success with implementing adoptable storage. After doing so, my GS7 (930T--T-Mobile branded, 32GB model) would randomly reboot--not the reboot loop that folks who have rooted phones run into--but a periodic reboot that didn't seem to follow any pattern, which could be as often as two or three times in an hour, and then no occurrences for as much as 6-8 hrs. To be sure I hadn't messed anything up, I factory reset the GS7 (used Recovery Mode/wipe data/factory reset), and reformatted the adoptable storage. The result of this process was to again be faced with random reboots. As soon as I again factory reset the GS7 and let it format/use the microSD card as external storage, the random reboots went away. My SD card is a PNY Elite microSDXC 128gb card (Grade 1, Class 10). I know that not all Class 10 cards are created equal, so is there perhaps another microSD card that would actually work? +++++++++++++++Original post: As a complete developer novice (for a few decades, anyway--my last significant development project was in FORTRAN), I was able to successfully follow the instructions, and enable adoptable storage on my Galaxy S7. One thing that panicked me at the very end of the process was that after going through all the steps, and seeing adoptable storage of my 128GB sdc on the S7, a reboot came back with a message along the lines of an indication that the SD card had to be deregistered, and would be reformatted. A second (and third) reboot got rid of this message, and the adoptable storage appears perfectly. BTW, some folks mentioned that there is at least one app in Google Play that will do this on non-rooted (as well as rooted), phones. I could not find one that does it for non-rooted phones. If someone has specific experience that contradicts this, please post details?