[ceph-users] High latency spikes under jewel

Hi, We experienced random and relative high latency spikes (around 0.5-10 sec) in our ceph cluster which consists 6 osd nodes, all osd nodes have 6 osd-s. One osd built with one spinning disk and two nvme device. We use a bcache device for osd back end (mixed with hdd and an nvme partition as caching device) and one nvme partition for journal. This synthetic command can be use for check io and latency: rados bench -p rbd 10 write -b 4000 -t 64 With this parameters we often got about 1.5 sec or higher for maximum latency. We cannot decide if our cluster is misconfigured or just this is a natural ceph behavior. Any help, suggestion would be appreciated. Regards, Bence -- --Szabo Bence --<szabo.bence@gmail.com>