On Thu, 5 Mar 2020, Chen, Haochuan Z wrote: This is a workaround to enable easier upgrades from ceph version when the ceph-osd daemon ran as root. When we first started running as user 'ceph', it was necessary to either (1) chown -R ceph:ceph all of the files on the HDD/SSD (filestore!), which could take hours, or (2) somehow conditionally make ceph-osd continue to run as root instead of dropping to user ceph. This flag allows that by checking whether the path is owned by the intended uid/gid to setuid too.. and if it doesn't match, we skip the calls to setuid (and continue running as root). This all happened back in the giant or hammer release, I think. But we need to keep this around since there are still OSDs with filestore that were created back then that are owned by root. sage