Le lundi 19 mars 2018 à 15:30 +0300, Sergey Malinin a écrit : > Default for mds_log_events_per_segment is 1024, in my set up I ended > up with 8192. > I calculated that value like IOPS / log segments * 5 seconds (afaik > MDS performs journal maintenance once in 5 seconds by default).
I tried 4096 from the initial 1024, then 8192 at the time of your answer, then 16384, with not much improvements... Then I tried to reduce the number of MDS, from 4 to 1, which definitely works (sorry if my initial mail didn't make it very clear that I was using many MDSs, even though it mentioned mds.2). I now have low rate of metadata write (40-50kBps), and the inter-DC link load reflects the size and direction of the actual data. I'll now try to reduce mds_log_events_per_segment back to its original value (1024), because performance is not optimal, and stutters a bit too much. Thanks for your advice! -- Nicolas Huillard _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
