In every Android smartphone there is some storage space provided by the manufacturer for the operating system files and some more space for the users to store their files. But the Android’s native File Manager app does not really show all the details as to how this space is being utilized. It just displays some basic information about the internal storage, external storage, attached SD cards and OTG disks (if they are attached via an OTG cable).
If you want to know some more details about the storage space in your Android device, then you can use the DiskInfo app for Android. This app is very singular in the way it displays the information about all the partitions on all the available disks in your Android phone. It shows disk usage and very detailed partition and storage information. It also displays total and free memory (RAM) and the swap partition (special partition used by Linux based systems).
As you can see in the screenshot, DiskInfo lists all the partitions on all kinds of storage devices attached to your Android smartphone. For each of the partitions, it displays the total storage size, used storage space as well as the free storage space. You can tap on any partition to see all the details in more depth. For example, it shows the mount point, file system type, access type, internal partition names, partition nickname and more.
In the settings for the DiskInfo app, you can customize it to display the mount path, partition name, file system, and display even the special partitions. You can also modify the way it calculates the free RAM available in Android.
Verdict: DiskInfo is a risk free way to view the internal partition structure in any Android device. Unlike some other methods, you do not have to root your device in order to gain the knowledge of partitions use in Android.
You can download the DiskInfo app in Android from https://play.google.com/store/apps/details?id=me.kuder.diskinfo&hl=en.