Android 5.1.1 Emulator File Systems

This section describes file systems used by the Android 5.1.1 emulator system. 9 file systems are supported in the Android emulator: /dev, /sys/fs/cgroup, /mnt/asec, /mnt/obb, /system, /data, /cache, /mnt/media_rw/sdcard, and /storage/sdcard.

Like any Unix systems, storage devices are organized as file systems. On the my Android 5.1.1 emulator, I can see the following file systems using the "df" shell command, which return disk space usages of file systems:

C:\local\android-sdk-windows\platform-tools>adb shell

root@generic:/ # df
df
Filesystem               Size     Used     Free   Blksize
/dev                   242.9M    24.0K   242.8M   4096
/sys/fs/cgroup         242.9M    12.0K   242.9M   4096
/mnt/asec              242.9M     0.0K   242.9M   4096
/mnt/obb               242.9M     0.0K   242.9M   4096
/system                541.3M   363.9M   177.5M   4096
/data                  541.3M   158.0M   383.3M   4096
/cache                  65.0M     4.3M    60.7M   4096
/mnt/media_rw/sdcard    31.5M     3.2M    28.3M   512
/storage/sdcard         31.5M     3.2M    28.3M   512

The "mount" shell command tells me how file systems are mounted into the file hierarchy:

C:\local\android-sdk-windows\platform-tools>adb shell

root@generic:/ # mount
mount
rootfs / rootfs ro,seclabel,relatime 0 0
tmpfs /dev tmpfs rw,seclabel,nosuid,relatime,mode=755 0 0
devpts /dev/pts devpts rw,seclabel,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,seclabel,relatime 0 0
selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
none /sys/fs/cgroup tmpfs rw,seclabel,relatime,mode=750,gid=1000 0 0
tmpfs /mnt/asec tmpfs rw,seclabel,relatime,mode=755,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,seclabel,relatime,mode=755,gid=1000 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
/dev/block/mtdblock0 /system ext4 ro,seclabel,relatime,data=ordered ...
/dev/block/mtdblock1 /data ext4 rw,seclabel,nosuid,nodev,noatime,nom...
/dev/block/mtdblock2 /cache ext4 rw,seclabel,nosuid,nodev,noatime,da...
/dev/block/vold/179:0 /mnt/media_rw/sdcard vfat rw,dirsync,nosuid,no...
/dev/fuse /storage/sdcard fuse rw,nosuid,nodev,noexec,relatime,user_...

Last update: 2015.

Table of Contents

 About This Book

 Installing JDK 1.8 on Windows System

 Installation of Android SDK R24 and Emulator

 Installing Apache Ant 1.9 on Windows System

 Developing First Android Application - HelloAndroid

 Android Application Package (APK) Files

 Android Debug Bridge (adb) Tool

Android File Systems

Android 5.1.1 Emulator File Systems

 Android 5.1.1 Emulator File System Hierarchy

 Android 4.0.3 File Systems

 AboutAndroid - Application to Retrieve System Information

 android.app.Activity Class and Activity Lifecycle

 View Objects and Layout Resource Files

 Using "adb logcat" Command for Debugging

 Build Process and Package File Content

 Building Your Own Web Browser

 Android Command Line Shell

 Samsung Galaxy Tab 3 Mini Tablet

 USB Debugging Applications on Samsung Tablet

 Android Tablet - LG-V905R

 USB Debugging Applications on LG-V905R Tablet

 Android Phone - LG-P925g

 USB Debugging Applications on LG-P925g Phone

 Outdated Tutorials

 References

 PDF Printing Version