Describe the issue: Update RHCS Compatibility Guide to reflect RHCS 4.2 requirements/support: https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/4/html-single/compatibility_guide/index
Please specify the severity of this bug. Severity is defined here: https://bugzilla.redhat.com/page.cgi?id=fields.html#bug_severity.