Do you want to use your MicroSD card as a real memory extension and install apps on it? Then you have to format it as internal memory. Unfortunately, some manufacturers such as Sony, LG or Samsung, can't do this from the factory. But if your smartphone has Android Marshmallow or newer, a command-line prompt will help. Prevent grief from system updates by following the new tips at the beginning of this article.
Android updates and Nougat issues with this method
Some readers have reported difficulties when installing system updates. The update to Android 7.0 Nougat especially does not seem possible with the manually partitioned MicroSD cards as described below. Our review devices, which have already been updated to Android 7.0 Nougat, do not even respond to the console commands shown below.
In the absence of documentation on the net, we can therefore only advise you to reverse the steps described below before a system update. Back up photos or music on your computer or in the cloud and free up as much memory on the SD card and smartphone as you can. Uninstall unnecessary apps and migrate your data back into the internal memory. Then format the MicroSD card as removable media. Only then is it safe to install an Android update.
There was no problem in Android 6.0 Marshmallow
When a MicroSD card is formatted as internal memory, apps can be completely stored on it. This means that if you download applications with a total size of 2 GB, then there should be 2 GB of space taken up on the SD card. If, however, the MicroSD card is only formatted as a backup memory, this is not the case, as PLATYPUS_DIARRHEA writes on Reddit.
With an option in Android Marshmallow, it is theoretically possible to treat MicroSD cards as internal memory. It allows the complete migration of your apps with their data. So the smartphone memory is actually expandable. Unfortunately, some smartphone manufacturers have omitted the menu option to format SD cards as internal memory for their Marshmallow variant.
Can't do it, it's not there
Just because the menu option is invisible doesn't mean that it doesn't work. A few days after the Reddit post, a command-line prompt became known, with which someone could also format MicroSD cards as internal memory in the Galaxy S7. We have successfully tested the instructions with the Samsung Galaxy S7, the Sony Xperia Z5 and the LG G4 while running Android 6.0 Marshmallow.
All three smartphones run from the factory, or via update, with Android 6.0 Marshmallow and have a slot for MicroSD cards. In addition, the menu option for formatting the MicroSD card as internal memory is missing. The entry is only available with HTC in the One A9 and with Motorola in all Moto smartphones.
Why Samsung, LG and Sony do not show us this menu option escapes me. I connected each of the three smartphones to the computer, and each had one MicroSD card inside.
Then I typed into the ADB tools the command-line commands that Paul O'Brien described in his blog post. As soon as you have the command line window open and the smartphone connected, you can enter the first command:
Now the command line is ready for you to issue system commands to your smartphone. In this case, we want to format the SD card or a part of its memory as an internal memory. Even if Sony, Samsung and LG deny us the possibility by a graphical user interface, we can still transfer the command to the smartphone as a console command. First, however, we need the ID of the SD card. We find these with the following command:
In my case, the disk is called 179.64. For you, perhaps, it is different. Note the exact identifier. In the next command, we will format and partition the MicroSD card. Your content will be deleted. If important files are on the card, copy them to another disk. If you want to keep the MicroSD card permanently in the smartphone, you can now partition all of your memory. To do this, type:
sm partition disk: 179.64 private
The operation takes several seconds or minutes, depending on the capacity of the memory card. If you want to use a certain percentage so that it can be read by other devices, you must exclude it from the private partition. The 50:50 partitioning command looks like this:
sm partition disk: 179.64 mixed 50
This is the end of Paul O'Brien's guide, but not the end of the work. If you now want to use the adopted memory as such, you must also migrate apps and data. This can be done through the storage section of your Android settings menu. Tap the MicroSD card, then move to the top right of the menu and click on Move data. You could not select this menu item before partitioning.
Now, and in the future, downloaded apps are fully written to the MicroSD card. Only system apps and updates use the internal memory. This means, you should never again get error messages due to lack of space if an app update is pending.
Where's the hook
MicroSD cards are not as fast as the internal memory of the smartphone. So don't waste money on the cheaper ones, and instead get yourself memory cards with a reasonable read throughput. The Extreme Pros and the Extreme Plus MicroSD cards by Sandisk have proved to be the best value for the money in our opinion. With 74 MB/s write throughput, you should not experience any delays in everyday life and profit from a considerably larger memory.
SanDisk Extreme PLUS 64GB microSDXC
Interestingly, only the LG G4 was able to correctly read the acquired memory. Samsung showed unnaturally high amounts of occupied memory and Sony's value was even negative. Nevertheless, we did not have any complications, and even when we were connected to the computer, we were able to access all of our data properly, even though we could only see the shared, and not private, portion of the memory there. Difficulties arose only when it came to system updates (see above).
Storage space gain: a complete success
We have subjected the manually partitioned devices to a uniform endurance test. We have installed Final Fantasy IX on all devices. The game is 1.8 GB in size. After installation, it's easy to see which of the two memories, internal or SD card, had its memory space used. In all cases, after the installation on the SD card, 1.8 GB less space was available. A success of this extent cannot be achieved with SD cards formatted as interchangeable memory, since complete data migration is not possible.
Compare the values of the internal memory and the SD card memory in the screenshot for proof.
Of course, the question is what happens when the MicroSD card is removed from the system. Actually, it creates a serious problem for your apps. After all, they can no longer access their data. Since the partitions with your operating system and the information for a factory reset are still stored in the internal memory, a removed or broken SD card can't do any harm. When we removed the MicroSD card, app icons were quickly replaced by a placeholder, which were immediately restored when reinstalled.
If you lose the SD card or it has a defect, your data is lost. Since these are encrypted as the internal memory, you should not hope for a data recovery. Instead, regular backups are appropriate. But this rule applies anyway. So have fun with the cheap memory expansion of your Marshmallow smartphone.
Safely remove an internally partitioned SD card
To safely remove the SD card from the smartphone, you must reverse the above process. Since your storage space on the internal memory is probably not sufficient, you first have to transfer pictures to another form of storage and uninstall apps. Then you go back to the Memory & USB settings and tap Move data under Internal memory in the menu. Then you go to the SD card and format it as mobile memory. Do both steps (backing up and formatting) so that your data cannot be lost and you can use the SD card with other devices.
Has this process worked for you? Which MicroSD card do you use? Let us know in the comments below.