On Tue, Mar 7, 2017 at 9:17 AM, Xiaoxi Chen <superdebu...@gmail.com> wrote: > Hi, > > From the admin socket of mds, I got following data on our > production cephfs env, roughly we have 585K inodes and almost same > amount of caps, but we have>2x dentries than inodes. > > I am pretty sure we dont use hard link intensively (if any). > And the #ino match with "rados ls --pool $my_data_pool}. > > Thanks for any explanations, appreciate it. > > > "mds_mem": { > "ino": 584974, > "ino+": 1290944, > "ino-": 705970, > "dir": 25750, > "dir+": 25750, > "dir-": 0, > "dn": 1291393, > "dn+": 1997517, > "dn-": 706124, > "cap": 584560, > "cap+": 2657008, > "cap-": 2072448, > "rss": 24599976, > "heap": 166284, > "malloc": 18446744073708721289, > "buf": 0 > }, >
One possibility is that you have many "null" dentries, which are created when we do a lookup and a file is not found -- we create a special dentry to remember that that filename does not exist, so that we can return ENOENT quickly next time. On pre-Kraken versions, null dentries can also be left behind after file deletions when the deletion is replayed on a standbyreplay MDS (http://tracker.ceph.com/issues/16919) John > > Xiaoxi > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com