Btrfs To Go Production-Ready In Oracle Linux

Btrfs, the quite promising next-generation Linux file-system that's been in-development for years by Chris Mason and others, is about to take on a big role within Oracle's Enterprise Linux distribution.

During his talk last week at the SCALE 10x LA event, Chris Mason of Oracle did mention that an error-fixing Btrfs fsck tool will be ready by next month. He mentioned a hard deadline of 14 February for this btrfs.fsck tool capable of fixing file-system errors because it must be ready for the next releases of Oracle Linux and SUSE Linux Enterprise. Chris confirmed that Oracle will be supporting Btrfs in their Linux distribution, which is derived from the Red Hat Enterprise Linux code-base.

When going through the talks from Linux.Conf.Au 2012, Avi Miller talked about the Btrfs file-system while Chris Mason was in Los Angeles. Avi Miller is a program manager at Oracle in Melbourne, Australia that handles release management of Oracle Linux and the Unbreakable Enterprise Kernel.

Besides parading the usual Btrfs features (copy-on-write snapshots, transparent compression, RAID support, SSD optimizations, etc) he also talks about the use of Btrfs within Oracle Linux. Besides repeating what Mason said back in the US, he does give a bit more detail. The next release of Oracle Linux (presumably it's the one being released next month) will provide installation support for Btrfs as the root file-system. This Btrfs root file-system support will be an official option in Oracle's RHEL-based Anaconda installer. However, this first release of 2012 won't make Btrfs as the default over the current EXT4.

With Btrfs becoming an official install-time option for the root file-system, obviously for proper support they need to have a proper btrfs.fsck utility ready in time to ship. Avi Miller also talked of "Btrfs is THAT fast all the time!", etc. Though an XFS developer was taking shots at Btrfs and EXT4 during Linux.Conf.Au 2012 as well.

When talking about the Btrfs support within Oracle Linux, it was usually mentioned with the Unbreakable Enterprise Kernel. The Unbreakable Enterprise Kernel is a version of the Linux kernel that they have optimized for Oracle software and hardware to be "a fast, modern, reliable kernel." In some performance tests they claim their customized kernel is 75% faster (or as much as 137% when it comes to SSD access) than the normal Red Hat Enterprise Linux kernel, which is still available as an option anyways in the Oracle Linux world. They also advertise their version of the Linux kernel having greater power management, more fine-grained CPU and memory resource control, and greater reliability. (More details for those unfamiliar with this kernel flavor from the Oracle web-site.)

Presumably Oracle is going to be shipping some back-ported Btrfs file-system patches within the next Unbreakable Enterprise Kernel release or some other changes to give it a competitive advantage over its stock RHEL-compatible Linux kernel, based upon the comments made by Miller with specifically mentioning this kernel flavor.

Oracle last year also expressed their intent to bring DTrace support to their Unbreakable Enterprise Kernel. It's not known whether this next Oracle Linux update will include the kernel and user-space support for DTrace, which was one of the key features of Solaris now being spread across Oracle products. But it looks like Oracle is going to further differentiate Oracle Linux from Red Hat Enterprise Linux and the other derivatives like CentOS and Scientific Linux.

Other distributions shipping with alternate install-time support for Btrfs on the root file-system include Fedora, Ubuntu, and openSUSE. The only major distribution shipping with Btrfs by default is/was Moblin, but it's expected that soon Fedora will switch to it as a default on new installations over EXT4. It's not clear whether this switch will still happen for Fedora 17 even with the availability of the btrfs-fsck utility, since there's still some blocking bugs, or if it will be postponed until Fedora 18 or Fedora 19.

Below is the Btrfs video from Linux.Conf.Au 2012. Stay tuned for more information about the upcoming Oracle Linux release and the greater role that Btrfs is about to play within the enterprise Linux world.