Im getting poor performance with 5 of my OSDs, Seagate Constellation ES SED (1) 10k SAS 2TB 3.5 drives. disk write latency keeps drifting high , 100ms-230ms on writes. the other 30 OSDs are performing well. avg latency 10-20ms We observe stats via “iostat -xtc 2” on CEPH server. w_await showing writes to disk latency. **anyone else have poor latency on SEDs? The disks were included on a server we acquired. Didn’t know they would be SEDs. I’ve read that seagate SED vs. non SED shouldn’t perform differently, but looks like they are awful. All the SEDs are in the newly added CEPH node. A Dell R510 with H700 raid card. all disks in entire cluster are R0, direct write to disk, no cache. The new server and disk control spec out at about 10x the ability and IOPs of other servers, so I suspect the SEDs. -Ed