Hi, I am getting relatively bad performance from cephfs. I use a replicated cache pool on ssd in front of an erasure coded pool on rotating media.
When reading big files (streaming video), I see a lot of disk i/o, especially writes. I have no clue what could cause these writes. The writes are going to the hdd's and they stop when I stop reading. I mounted everything with noatime and nodiratime so it shouldn't be that. On a related note, the Cephfs metadata is stored on ssd too, so metadata-related changes shouldn't hit the hdd's anyway I think. Any thoughts? How can I get more information about what ceph is doing? Using iotop I only see that the osd processes are busy but it doesn't give many hints as to what they are doing. Thanks, Erik. _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
