When using overlay(fs) as the docker storage driver, the backing xfs filesystem needs to be formatted with ftype=1 (d_type support enabled):
https://linuxer.pro/2017/03/what-is-d_type-and-why-docker-overlayfs-need-it/

If d_type support is not enabled, it can lead to erroneous behaviour (e.g. attempt to remove a directory fails with "rm: cannot remove 'path': : Directory not empty" message):
https://github.com/moby/moby/issues/27358

rkt and moby contain this check already:

• https://github.com/rkt/rkt/pull/3105/files#diff-b5ccff3f3777d1b87c84277733a8c04fR393
• https://github.com/moby/moby/pull/27433
  Also AFAICT this check will become a fatal warning in some of future versions of Docker.

Situation in Red Hat Enterprise Linux:

• RHEL-7.1 (https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/7.1_release_notes/#chap-Red_Hat_Enterprise_Linux-7.1_Release_Notes-File_Systems) overlayfs is TP, only ext4 is supported as the lower file system => not an issue,
• RHEL-7.2 (https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/7.2_release_notes/#chap-Red_Hat_Enterprise_Linux-7.1_Release_Notes-File_Systems )
  overlayfs remains TP, only xfs is supported as lower layer file system. It needs to be formatted with "-n ftype=1" option enabled,
• RHEL-7.3 and above (https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/7.3_release_notes/#technology_previews_file_systems) overlayfs remains TP, only xfs is supported as the lower layer file system. "-n ftype=1" is enabled by default on RHEL-7.3 and above due to xfsprogs rebase to upstream 4.5.0 version:
  • https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/7.3_release_notes/#new_features_file_systems
  • https://bugzilla.redhat.com/show_bug.cgi?id=1309498