[ceph-users] Re: CephFS: What is the maximum number of files per directory

Just an anecdotal answer from me... You want as few files as possible. I wouldn't go beyond a few hundred files in a dir. Seeing ~1s for each 1,000 files when I "ls". But this is in a pretty idle directory. When there were files actively being written to those dirs and being read, just doing "ls" on the directories was very very slow (in the order of minutes) I have a single MDS setup with cephfs metadata on SSDs. MDS cache at 20GB, 6 million inodes, approaching 10k reqs/s. $ for i in `ls --color=none | head -50 | tail -10`; do echo; echo -n "file count in dir: "; time ls $i | wc -l; done file count in dir: 4354 real 0m4.129s user 0m0.029s sys 0m0.179s file count in dir: 3064 real 0m2.847s user 0m0.027s sys 0m0.127s file count in dir: 1770 real 0m1.658s user 0m0.026s sys 0m0.075s