Hello, Thanks for your answer. Both OSDs and client are CentOS 6.3 with 3.7.1 kernel. And yes, the script creates empty loop devices of different sizes. MDS & MON are on one of the 2 OSD hosts. I already try to put them on a separate server. I know that CephFS is not considered as stable yet, but... i was hoping... Thanks, Alexis -- 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