Adoptable storage, using micro SD card as internal storage, is one of the most welcomed new features in Android Marshmallow.
- use the micro SD card as internal storage. The micro SD card will be merged with phone internal storage. This usage is intended for owners who are facing phone storage issues.
- use the micro SD card as portable storage. This usage is designed for owners who need move files among devices.
This guide will show you detailed steps to use micro SD card as internal storage in Android Marshmallow.
Step 0: decide whether you want to use micro SD card as internal storage in Android Marshmallow.
Although you can switch back and forth between using SD card as internal storage and as portable storage at any time, it may take some time to back up files on it. And you also need format the micro SD card whenever you switch the option.
So, you’d better think about your need carefully whether the phone internal storage will be an issue for you in next 12 months.
If your phone only has less than 16GB storage and you need install some games, you probably should consider to use SD card as internal storage to expand internal storage.
Step 1: Choose to use micro SD card as internal storage in Android Marshmallow
After you update your phone to Android Marshmallow or after you insert the SD card first time, you will get a notification like below.
You should NOT ignore the notification if you see it. Even if you use the micro SD card as portable storage, you still need set it up once. Failing to setup SD card properly may give many unexpected problems in the future.
Tap Set up as shown below.
Now, you are given 2 options to use the micro SD card in Android Marshmallow devices.
Please note, some vendors may disable the option to use micro SD card as internal storage. For example, in Samsung Galaxy S7 and Galaxy S7 edge, you can only use micro SD card as portable storage.
In this guide, I assume this feature (using micro SD card as internal storage) is not disabled by the manufacturer.
Tap Use as internal storage as shown below. Then tap Next.
Step 2: Format the SD card
To use micro SD card as internal storage, the SD card must be formatted. This means all data on the micro SD card will be erased. You should backup them if there are any files you may want to keep.
In addition device encryption is enabled by default in Android Marshmallow. So, the micro SD card, after formatted as internal storage, cannot be used on any other devices until you format it again.
This warning is clearly stated in the page after you select to use micro SD card as internal storage as shown above(SanDisk micro SD is used as an example. You should see the brand of your own SD card):
After formatting, this SanDisk SD card will only work in this device.
Formatting erases all data currently stored on the SanDisk SD card. To avoid losing the data, consider backing it up.
Tap Erase & Format as shown above to proceed.
Now, the phone will start to format the micro SD card.
A progress bar for the formatting will be active as shown below.
When the SD card is being formatted, you should NOT remove the SD card. It may damage the SD card!
Normally, it should just take one or two minutes to format a micro SD card.
Step 3: IMPORTANT!!! Move data to new storage (micro SD card).
After the micro SD card is formatted, you are given the option to move some files to micro SD card.
Please note, when you choose to use micro SD card as internal storage, you cannot control which files are saved in SD card, and which files are saved in the phone storage.
It will be always decided by the system based on many factors, for example, available phone storage and file type.
You can choose to move them now, or move them later.
You should always choose” Move now”. This is important. If you choose Move later, the system will continue to use phone storage, not SD card!!!
Tap Move now, then tap Next as shown above. The Next button is grayed out unless you make the decision.
Don’t exit at this stage!!! If you accidentally exit the procedure, you must start again.
Now, the system will try to move some files from phone storage to SD card.
As mentioned, the files to be moved to SD card are determined by some algorithms in Android Marshmallow. If your phone storage is critically low, it will try to move more automatically.
Before moving data to micro SD card, the system will estimated the size of files to be moved.
For example, as shown below, system decides to move 108MB files to the micro SD card. This will free 108MB on the phone storage.
Tap Move as shown below to start moving data.
Now, a progress bar on data moving is active. The process highly depends on the size of files to be moved.
It usually take less than a few minutes. Be patient.
Some apps may not work when data moving is in progress. So, refrain from using phone for this one or two minutes.
Step 4: Enjoy expanded phone storage.
Once the files are moved to SD card, you can tap Done button as shown above.
From now on, the micro SD card becomes part of the phone storage system.
Technically, it can be used for any apps and data. But in Android Marshmallow, normally media files and app data are actually saved in the SD card.
When your actual phone storage is too low, some apps will be moved to SD card automatically. The bottom line is that you should not worry about insufficient phone storage as long as your micro SD card have space.
The pre-installed apps are always in the physical phone storage, not SD card.
You can check the storage usage in Settings– Storage & USB as shown above.
For example, as shown above, my 8GB Moto G 3rd Gen becomes a 40GB phone.
Please note, you can only see the SD card storage here. All other file explorer apps (e.g., ES file explorer) should display phone storage+SD card as one storage.
And again, you cannot specify file saving locations as SD card or phone storage in any apps.
How to change from portable storage to use micro SD card as internal storage in Android Marshmallow
If you currently use micro SD card as portable storage, you can easily convert to use the micro SD card as internal storage.
You should backup important files on the SD card. Converting the micro SD card as internal storage will remove all files on the card.
Go to Settings —Storage & USB .
Tap SanDisk SD card as shown below (SanDisk is used as an example. You should see the brand of your own SD card).
Then tap menu key (3 vertical dots) near top right.
Among the menu items, tap Settings as shown below.
In the next page, tap Format as internal as shown below.
Then you will go through the similar procedure to format the micro SD card as internal storage as mentioned above.
As mentioned, the micro SD will be formatted and encrypted. All files on it will be erased, and you cannot use the micro SD on other device unless you format it again.
What happens if I reset (factory data reset) the phone?
If you set the micro SD card as internal storage, after resetting the phone, NO device, including your own phone, can read the SD card.
All data in the SD card were encrypted when you chose to use the SD card as internal storage. The encryption key was saved in the secured location in the internal storage.
But if you reset the phone, all data in the internal storage are erased, including the encryption key.
So, NO device can read the SD card. You have to format the SD if you want to use the SD again.
It is important to back up your data (including your files and data) in the phone before resetting it. Back up, back up and back up.
Can you use micro SD card as internal storage in Android Marshmallow device now? Can you convert from portable storage to internal storage for the micro SD card in Android Marshmallow device?
If you have any questions or problems on how to use micro SD card as internal storage in Android Marshmallow device, or to convert from portable storage to internal storage, please let us know in the comment box below.
The community will help you.
For any questions or problems with Android Marshmallow, please check our Android Marshmallow Guide page.
If your question is about Android Lollipop, please check out Android Lollipop Guide page.