Android will be using ext4 starting with Gingerbread | Hacker News Reader

Android will be using ext4 starting with Gingerbread

thunk.org

33 pointsshrikant6 comments

One nice thing about well written, vetted, and regressed open source - the decision to ship Android on ext4 apparently occurred without discussing it with Theodore Ts'o, because there was really no need to. The product (in this case, a file system) spoke for itself, and primary developers only involvement is in their contribution - the file system stands on its own.

Compare this to deploying on a closed source/licensed product, in which conversations with the vendor regarding their future plans, support, and possibly code-escrow in case they went out of business.

I assume this marks the end of raw nand flash devices in the next generations of Android phones ?

One of the comments clarifies that ext4 won't be used for the entire storage subsystem:

# 23 Brian Swetland Says: December 13th, 2010 at 8:35 pm Yup, our main motivation here was to select a filesystem to work on top of emmc which has built-in block rotation and translation and looks like a regular block device (similar to ssds on desktop systems). At this point ext4 seems to our eyes to be the most stable and performant option of the standard linux filesystems that support full unix permissions and semantics.

We use ext4 for the system image (read only), and the local user data and cache partitions (read-write). A separate FAT partition is used for media storage, since that’s still the least-common-denominator needed for USB Mass Storage to “Just Work” with PCs and Macs. For post-gingerbread we’re investigating alternatives to UMS which would allow us to stop using FAT for media/external storage entirely.

This might be a good place to ask for a book recommendation: where can I read a comprehensive readable intro to linux, which would presumably cover things like types of file systems?

UNIX and Linux System Administration Handbook (now out in fourth edition) is a pretty good book. It combines a lot of introductory material, but also mentions broader unix topics - AIX/HPUX/Solaris all get an honorable mention. The topics they pay attention to are all pretty relevant.

A classic. There's a new version which just focuses on current Linux OSs, which the OP may find more practical. AIX and HPUX are fairly rare these days and the most popular version of Solaris (8) is in legacy support.

http://www.amazon.co.uk/Linux-Administration-Handbook-Evi-Ne...

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