It's all about expected disk sizes in 10 years time (when RHEL 7 main support ends). Ext4 scales up to around 16 TB -- I know it theoretically can support a much larger volume size, but in practice it doesn't work so well. XFS handles tens of terabytes without a problem and Red Hat has been supporting huge XFS volumes for years with many customers (who in earlier versions of RHEL paid extra for that support).
http://lwn.net/Articles/573690/
Dave is a redhat employee.
Dave Chinner's talk is great:
http://www.youtube.com/watch?v=FegjLbCnoBw
Re:Red Hat Enterprise Linux 7 Beta
by conception on Wednesday December 11, 2013 @08:52PM
(#6892362)
Their gluster server offering also uses XFS, so probably for support reasons, they saw XFS had better long term support for both sets of users.
Why do you suppose they went with XFS? Ext4 seems like the defacto file system these days, but I know a lot of people seem to prefer XFS for one reason or another. It's a surprise to me that RHEL decided to default too it.
Anybody care to shed some light?