What file system does Android use?

android ext4
qyanqing picture qyanqing · May 30, 2014 · Viewed 21.7k times · Source

Which file system does Android use? I have read both ext4 and YAFFS2.

Answer

Greg Sherman picture Greg Sherman · May 30, 2014

Android originally used YAFFS2 as the file system. After Android 2.3, the file system became ext4.

YAFFS2 is usually used for NAND flash in embedded systems such as mobile phones. It includes wear-leveling and a GC mechanism specifically for NAND flash, but it is only single-threaded.

According to an ARS Technica article, the reason that Android switched to ext4 from YAFFS2 for its file system is because YAFFS2 is single-threaded, and "would likely have been a bottleneck on dual-core systems." Android, even back in 2010 was looking forward when many cores could be used in Smartphones. Looking back, it was obvious that this was the right decision. Smartphones went to Dual Core around the time of Galaxy S2. More recently most Smart Phones are released in Quad-Core configuration, with 6 and 8 core configurations on the horizon.

Related questions

Can't start Eclipse - Java was started but returned exit code=13

I am trying to get my first taste of Android development using Eclipse. I ran into this problem when trying to run Eclipse, having installed version 4.2 only minutes ago. After first trying to start Eclipse without any parameters to specify …

Read More
How do you close/hide the Android soft keyboard using Java?

I have an EditText and a Button in my layout. After writing in the edit field and clicking on the Button, I want to hide the virtual keyboard when touching outside the keyboard. I assume that this is a simple …

Read More
How to get current time and date in Android

How can I get the current time and date in an Android app?

Read More