An interesting under-the-hood change has come with Android 2.3 Gingerbread – a new file system called ext4. You may have heard of it, it’s fairly common among Linux distributions. Ext4 is already running in Google’s massive data centers and it will slowly be making its way to their mobile OS, starting with the Google Nexus S…
The reason why Google chose ext4 for their data centers has mostly to do with the file system’s improved support and performance when dealing with large files and large storage drives. That isn’t a problem on mobile phones but there are other benefits for the mobile.
Most Android devices out there are using YAFFS, which is a file system specifically designed for flash storage. Its problem is that it’s single-threaded – that is, it won’t see a performance boost on those rumored dual-core droids that so often grace our news section lately.
Ext4 will offer a performance boost even on single core CPUs but with two cores the difference will be even more pronounced.
On the bad side, there are some concerns that ext4 will increase the chances of data loss. However, Theodore T’so (a key ext4 dev and current Google employee) says that users shouldn’t worry – vendors do extensive testing before shipping a product and a well programmed app shouldn’t have problems anyway (unless something drastic happens, like the user removing the battery while the app is running).
Check out the Android Developers blog post and a couple of Theodore T’so blog posts for more details (warning: programmer talk ahead).
The more adventurous, tech savvy users can check out the XDA-Developers forums – they have custom ROMs (including the popular Cyanogen ROM) for various phones that enable ext4.