I was reading through the Gluster 3.2.5 release notes today and came across the following blurb:
Red Hat recommends XFS when formatting the disk sub-system. XFS supports metadata journaling, which facilitates quicker crash recovery. The XFS file system can also be de-fragmented and enlarged while mounted and active. Any other POSIX compliant disk file system, such as Ext3, Ext4, ReiserFS may also work, but has not been tested widely.
This is pretty cool, and it’s the first time I recall seeing Redhat recommending XFS over EXT3 or EXT4. Good to know!