Hello folks, I have a question: I know files get mapped to objects and those objects to OSDs but how exactly do we go from one to the other? What I mean is, given the filename I want to access how does Ceph find the relevant objects? What exactly does CRUSH do? Supposedly, the client first asks the MDS for an inode number, what then? How are the object and PG IDs constructed and where exactly does CRUSH come in? My impression is that the OID is made from the name, inode and probably some kind of information about the striping of the file, what about the mapping of an object to a PG? Are PGs mapped to OSDs by means of CRUSH, or are objects mapped to PGs by CRUSH? How are PGs assigned to OSDs then? Could someone clarify this part for me? Thanks in advance -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
