Linux 3.4 follows the Linux 3.3 release by two months and is now officially “stable” after Linux creator Linus Torvalds pushed out seven release candidates.
“I think the 3.4 release cycle as a whole has been fairly calm,” Torvalds wrote in his release announcement. “Sure, I always wish for the -rc’s to calm down more quickly than they ever seem to do, but I think on the whole we didn’t have any big disruptive events, which is just how I like it.”
In terms of features, enhancements to the Btrfs filesystem top the list. The Btrfs effort was initiated by Oracle engineer Chris Mason as a means to provide a more robust filesystem for Linux than the default Ext4 system. Linux Kernel Btrfs first debuted in March 2009 as part of the Linux 2.6.29 kernel and has been steadily evolving ever since.
Linux 3.4 adds a new btfs-restore utility for Btrfs, which can help to recover data from a filesystem that is not mountable. Performance in Btrfs has also been improved with support for metadata blocks of up to 64KB in size, up from the previous 4KB.