Thursday, December 8, 2016

Android Partitions: What they are and why they are needed?

Like with any other desktop or mobile OS, Android file system is made up of several partitions. Here we will be posting Android partitions list with brief description of each. These include internal as well as SD card partitions. Purpose is to guide a beginner level user in better understanding Android partition and the file system to better manage their device.

Android Partitions (Internal & SD Card Partitions)

Here is a list of internal partitions in Android:
  1. /boot
  2. /cache
  3. /data
  4. /misc
  5. /recovery
  6. /system
And here are the external partitions:
  1. /sdcard + (sdcard2 is some cases)
  2. /sd-ext
So, there are total of 8 partitions, 6 of which are internal while 2 are external. Of all these 8, only 1 partition. sdcard, is found on all devices while others may be found on selected devices only. All of these are explained below:

Boot Partition (/boot)

As its name suggests, boot partitions contains the files that facilitates the boot process of Android device. The ramdisk and the kernel are also found on this partition.
If you wipe boot partition, you will still be able to boot your device in Recovery mode. It’s recommended to not to do it unless you have a ROM with boot partition in it.

Cache Partition (/cache)

Android Cache partition stores logs and frequently accessed app data. Downloads from Google Play Store are also stored in this partition.
Clearing / wiping this partition does not affect your Android device in any way. It just frees up some space.

Data Partition (/data)

This is where user data is stored. This includes everything from user settings & customizations, apps that you have downloaded and installed, your messages (SMS / MMS) as well as contacts.
Wiping data partition will restore your phone to factory settings, removing all apps, messages and user settings from the device.

Misc Partition (/misc)

This partition contains miscellaneous hardware settings for your device. These files are mandatory for your device to function properly.
If you wipe misc partition, your Android device will not function properly and may note boot at all.

Recovery Partition (/recovery)

This partition lets you boot in recovery mode. While in recovery mode, you can perform plenty of functions like wiping your data / userdata partition to restore your device to factory settings and clearing cache partition.

System Partition (/system)

As the name indicates, all the files pertaining to OS are stored in this partition. This also includes all the system apps that are part of Android.
Clearing / Wiping System partition will remove Android from your device. However, you may still be able to boot into recovery or download mode and flash a new ROM.

SDCard Partition (/sdcard)

The /sdcard partition on Android refers to the space that is available to users to store their files and data. Depending on your device, there may be several sdcard partitions. On devices with external SD card slot, the /sdcard partition represents the internal storage device. For external SD card, you can find a different partition /sdcard2 or a directory within sdcard partition like /sdcard/sd.
You can safely wipe sdcard2 partition as there’s no system data stored on this partition. The sdcard partition may contain user data and app settings / data stored by different apps. Wiping /sdcard partition will just wipe some app settings and user data and in no way interrupts system’s boot process or functionality.

SD-Ext Partition (/sd-ext)

This is an additional partition of the sdcard partition which is used mostly by custom ROMs and mods. This works as /data partition of the /sdcard, storing user data and settings that is typically stored on /data partition. This partition is helpful for devices with limited internal memory as the user data and settings are stored on SD card and not on internal storage.
Wiping sd-ext partition, if you have data stored on it, is same as wiping /data partition. You will lose settings, contacts, messages and any other data stored on that partition.