Hi Marvin, On Thu, Jan 17, 2019 at 12:36 AM Marvin Zhang <fanzier@xxxxxxxxx> wrote: > 1. In current design, system cannot create more than 1 fs in a pool. > In Feature #15066(http://tracker.ceph.com/issues/15066) will handle > this issue. Filer::write() will identify the RADOS object by > poolID+OID. If we want to support multi-fs in a pool, we need to add > prefix tag on OID, such as fs1:100000000 .PoolID still comes from > layout information, which comes from mdsmap. Is it correct? Yes. See this old ticket: http://tracker.ceph.com/issues/5520 The kernel client would also need updated. > 2. If the Feature #15066 resolved, can sinlge active MDS support > multiple FS? In my opinion, an active MDS has a MDSRank object, which > has a MDLog. We need to change that MDSRank object has multi MDLog. > One MDLog correspond one fs. It seems no issue tracking this problem. If I understand your question correctly, we have no current plans to make a single MDS take on ranks for multiple file systems. Although attempts have been made in the code -- when easy -- to make this feasible in the future. This would probably be a significant amount of work with dubious benefit in the current age of containerized services. -- Patrick Donnelly
