Linux kernel developer Ted Ts'o who has joined Google, leaving behind his previous role as CTO of the Linux Foundation, announced that Google will upgrade its storage infrastructure from Ext2 to Ext4.

Ted Ts'o, an expert on filesystem development, played a central role in creating Ext4, the latest generation of the Linux filesystem.

After extensive testing Google discovered that the Ext4 filesystem offeres significant performance advantages over Ext2 and nearly rivaled the high-performance XFS filesystem during tests. Ext4 was chosen over XFS because it would allow Google to do a live in-place upgrade of its existing Ext2 filesystems, as stated by Google engineer Michael Rubin.

"The driving performance reason to upgrade is that while ext2 had been 'good enough' for a very long time the metadata arrangement on a stale file system was leading to what we call 'read inflation'. This is where we end up doing many seeks to read one block of data. In general latency from poor block allocation was causing performance hiccups," Michael Rubin wrote.
"For our workloads we saw ext4 and xfs as 'close enough' in performance in the areas we cared about. The fact that we had a much smoother upgrade path with ext4 clinched the deal."