Dear ceph users, I set up a new cluster: - Debian stretch - ceph 12.2.7 - 3 nodes with mixed mon/osd - 4 hdd 4TB osd per nodes - 2 SSDs per nodes shared among osds for db/wal - each OSD alone in a raid0+WriteBack Inside a VM I get really good writes(200MB/s, 5k iops for direct 4K rand writes), but with rand reads, device is 100% io wait with only ~150 IOPS of avg size 128K. I tried same workload using fio on rbd volume, same results :( I played with VM read_ahead without any changes. I also disable most of ceph debug, no change. Any hints to solve this? Here is the ceph.conf used: https://owncloud.home-dn.net/index.php/s/swZsgeFGF2ZfPB2 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |