Your storage isn’t infinite so you eventually start running low at some point. Once you start running low or have maxed out your available storage, lagging is one of the first things you’ll encounter. One way to quickly free up space without deleting stuff is to move some files to your external SD card. Adoptable storage made this even easier by making your external SD card act as an extension of your internal storage.
A while back, you needed root access with apps like Link2SD and App2SD to pull this off. With Adoptable Storage, you don’t need to root.
What is Adoptable storage
This was introduced in Android 6.0. It enables you format and adopt an external storage to act as internal storage. The adopted device is encrypted to work only with the device that adopted it. The adopted storage can safely store your apps and app data.
To avoid data loss / corruption, its better to adopt an SD Card on your smartphone instead of a USB device. You could however consider a USB device for a Smart TV or TV Box since they tend to be much less mobile than a smartphone.
Note that Adoptable Storage can’t be used on models with File Based Encryption (FBE). Once adopted, you can no longer use the SD card to move files between devices as you’ll be prompted to format it first. You’ll therefore need to dedicate an SD card to adoption.
How do I enable Adoptable Storage
I’d dropped a guide on setting up Adoptable Storage on your Android device so feel free to check it out and follow if your device model and Android version supports it.
Is there any downside of using Adoptable Storage
If your device contains data you can’t afford to lose then I wouldn’t recommend implementing Adoptable Storage. Should the SD card get corrupted (which is more likely if using a low end one or have frequent read-write operations) then all your data is gone.
I’ve witnessed two such cases and in both, nothing could be retrieved, not even from internal storage. No app could read or write anything. Screenshots couldn’t be saved, pictures couldn’t be taken, couldn’t even do a factory reset under Settings because the Settings app kept crashing. It took downloading the firmware and flashing to revive the phones.