My understanding is that XFS is now default because it has far better support than ext4 for large (hundreds of TB to PB) volumes. In addition, RedHat employs many core XFS members.
With the quashing of the slow metadata performance (http://lwn.net/Articles/476263/), XFS seems to be all-round just as good as ext4 but with more future-proofiness for large volumes. Keep in mind that RHEL releases are supported for around a decade.
With the quashing of the slow metadata performance (http://lwn.net/Articles/476263/), XFS seems to be all-round just as good as ext4 but with more future-proofiness for large volumes. Keep in mind that RHEL releases are supported for around a decade.