Hi list, I came across some strange MDS behaviour recently where it is not possible to start and MDS on a machine that happens to have the hostname "admin". This turns out to be this code https://github.com/ceph/ceph/blob/master/src/common/entity_name.cc#L128 that is called by ceph-mds here https://github.com/ceph/ceph/blob/master/src/ceph_mds.cc#L116. Together with the respective systemd unit file (passing "--id %i") this prevents starting an MDS on a machine witht he hostname admin. Is this just old code and chance or is there a reason behind this? The MDS is the only daemon doing that, though I did not check for other but similar checks in other daemons. Best, Jan -- Jan Fajerski Engineer Enterprise Storage SUSE Linux GmbH, GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg)