As a follow on to LU-11376, which has defined a new "foreign" format of LOV/LMV for file/dir to allow external storage reference from Lustre namespace (with the benefit of existing LOV/LMV pre-fetch mechanism, DLM protection and client/server multi-stages caching), this ticket documents a specific usage and implementation for DAOS purpose.

To be able to reference and access DAOS data, we first need to register both a pool and container uuids inside the foreign LOV/LMV, respectively for file/dir.

Then to permit transparent and quick access to DAOS containers from Lustre namespace, an extension to the Lustre Client needs to be implemented. A first try is to allow this as a symlink-like behaviour to DAOS fuse mounts.