Description of problem:

This documentation:

https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/3/html/ceph_file_system_guide/deploying-ceph-file-systems#creating-ceph-file-systems-with-erasure-coding-fs

suggests creating a file system with an erasure coded data pool, as the default data pool. (The default data pool is the one used during file system construction.)

We should amend the docs to advise **always** using a replicated pool for the default data pool and use `ceph fs add_data_pool` to add an additional erasure coded pool. A directory/file layout can be used to store data in the supplemental EC data pool.

Version-Release number of selected component (if applicable):

3.3