Description of problem: With the new provision of deploying EC pools ( 4+2, 4+3 ) on a 4 node cluster, Custom CRUSH rules become very important, without which, All the PGs could be placed on OSDs from same host, and losing a host might trigger data loss. To tackle this, we need Raise a Warning when an EC pool is created with failure_domain as OSD, Warning the user of potential case of Data loss scenario. Without Custom CRUSH rule, if a 4+2 pool is created on a 4 node cluster with failure domain OSD, we have observed that sometimes upto 4 OSDs from same host is picked for an acting set. If this node goes down, the data recovery is not possible. We should have a warning generated when such EC profile based pools are created without Custom CRUSH rules. Version-Release number of selected component (if applicable): How reproducible: always Steps to Reproduce: 1. Deploy a 4 node RHCS cluster. 2. Create a 4+2 EC rule, with failure domain as OSD. 3. Create a pool, observe PG placement. Actual results: No warnings generated for above scenario Expected results: Warnings to be generated for the issues. Additional info: