How to pin a CephFS directory to a specific MDS

Starting in Red Hat Ceph Storage 3, CephFS offers the ability to have the load of metadata lookups distributed across multiple MetaData Servers ( MDS ). Normally this distribution of lookup load is distributed automatically, however it can be useful to manually set a given MDS as being responsible for a specific data path in CephFS.

NOTE: Multi-active MDS is not genera...