Centos 7, XFS vs EXT4

[marksandford]

Moved from ISLE issues: https://github.com/Islandora-Collaboration-Group/ISLE/issues/101

When creating a CentOS host the default filesystem is now XFS. XFS out-of-the-box has known, but very transient, issues with Docker. In our case, my Dockerized icg_web_test was unable to open web resources inside our campus firewall, a problem I could not repeat on other nodes. The problem was our new CentOS Docker platform was built with XFS and the d_type (directory type setting) was NOT overridden. In the end we had to rebuild the CentOS 7 host from scratch and specify it with an EXT4 filesystem. All problems solved.

I didn't use the following resource when researching/fixing our problem, but this seems like it might be a useful reference: https://community.centminmod.com/threads/using-docker-on-centos-7-choose-ext4-over-xfs.12492/