[Samsung Galaxy A3, A5, A7 (2017) Questions & Answe] Flo3960:
Hello!

This is my first post in this forum, please be indulgent if I don't understand some stuff or abbreviations immediately. :)

I recently bought a Galaxy A3 2017 (SM-A320FL) to replace my old one with shattered screen and back cover. I tried the new Poco X3 for two weeks, but I wasn't satisfied with it since it was just wayyy too large for me, and also the phone speaker was unbearably loud (all people around me could follow the conversation on phone, even on lowest volume), which then led to the decision of sending it back and buying another used A3 2017 in good condition, as I was very satisfied with it, except of limited internal storage which continued to be an issue over months and years. And since the spare parts would have cost the same as the smartphone costs used at the moment, the decision was easy.

To avoid the single problem I had with the old phone, I wanted to root the phone right from the start so I could adopt the SD card as internal storage and/or change the folder some apps (especially WhatsApp) are storing their data and media in. Since the phone is factory reset and I have the other one which is still functioning, I don't have to take much care while trying things, which is great. I took yesterday evening until late night for that plan, and although a lot of threads and posts I read said that rooting the stock OS with latest update of Android 8 is not possible, I did it after some trial and error with flashing the custom recovery TWRP through Odin and then flashing SuperSU through TWRP. If a tutorial is needed, I'd happily write down how I did it, just ask.

But I still have a problem with adopting the storage. And as far as I understood, this is related to the storage encryption of Android/Samsung. Please explain if someone knows, I'd really like to understand the mechanisms that make all of this so laborious. I tried to mount the storage in TWRP when I started it first after flashing (it persists btw, as some people said it is gone and no recovery system can be found after the phone booted normally once, why?), but ran into the problem of "internal storage (0MB)". This was solved by wiping it, then I was able to mount the SD card as internal storage and the internal storage also was shown with a reasonable size in MB. I then started the phone which was obviously factory reset by the wiping. Unfortunately I couldn't see any results in the OS (does stock Android or file manager even show these changes in some way?) and also noticed the adopted storage was not anymore adopted when inspecting it in the TWRP recovery and again the internal storage was at 0MB. I then stumbled upon the app "Root Essentials" which is said to be able to adopt the storage, but needs a zip file which must be flashed by the recovery for that process. I tried it, but the flashing process does not work, as it can't find an installation of the app - my guess is, that this also is related to encrypted storage and the 0MB problem, how should the flash be able to look for something in encrypted space?

Soo, my problem now is, that I want to adopt the storage and don't know how to continue & where to begin. I also don't know if that app "Root Essentials" is any good, just read it at several places while googling so gave it a try. The phone is rooted with TWRP (0MB problem persisting) and stock OS now, and the adoptable storage per se is no must-have for me - if there is any other solution to migrate apps and more importantly their data to the SD card, please let me know, I'd be perfectly fine with that also.

Thank you! :D

Flo