The btrfs File System

One of the great things that I love about Ubuntu is there 6 month release cycle.  It allows you to try out features that you normally would need to integrate into your distrobution yourself.  This post isn't about Ubuntu however, it's about the up and coming file system...btrfs.  I will start by saying that it isn't currently stable so please if you try implementing it, back up your system first!  The file system is being built as a replace for the ext family file system that is used as a default in a majority of Linux distrobutions.  Having a new file system however will allow for the integration of missing features from current Linux distros.  Let's look at some of the features that btrfs provides.

• Online volume growth and shrinking
• Online block device addition and removal
• Snapshots (w00t w00t!)
• Subvolumes
• In-place conversion + rollback features

While this isn't all of the features that btrfs offers it is some of the most important improvements that this new file system can offer.  The developers are also looking to work data deduplication into the feature set for the stable release.  The reason that I mentioned Ubuntu at the beginning of this post is that the developers are currently working toward making btrfs the new default file system for Ubuntu.  Since Red Hat has an 18 month release cycle (which is more like 3 years at the moment), and that RHEL 6 is coming out in October of this year it won't have the new file system.  The good news though is that you can upgrade any ext family file system to btrfs, which is a huge plus!  Another big benefit is that you will be able to run file system checks online and offline.  This reduces the downtime needed during maintenance (making your customers happier).

Personally I think that the addition of snapshots to the file system is the best feature.  Things like volume shadow services have been around in Windows for a while and it is nice to see that Linux is finally getting support for something similar.  This will help many admins with their users that tend to "delete things".  As of right now there is still no release date set for the stable release however there are many users that have been running the btrfs file system with no issues.  I will warn you again however not to use this on production systems as it is not stable (QA or DEV is always a good choice).  Between the large feature set and scalability that this file system provides I'm looking forward to the stable release as it will be a welcome upgrade to the current file systems in use today.

Here is the link showing how the conversion alogrithm works and how you can convert your ext3/4 file system to btrfs (and roll back if you'd like too).

https://btrfs.wiki.kernel.org/index.php/Conversion_from_Ext3

Additional Reading

https://btrfs.wiki.kernel.org/index.php/Main_Page
http://en.wikipedia.org/wiki/Btrfs