By default CEPH reports this if during last 24h one operation takes longer thant 30 seconds
ceph config get osd bluestore_slow_ops_warn_lifetime ceph config get osd bluestore_slow_ops_warn_threshold
Tune it:
ceph config set osd bluestore_slow_ops_warn_lifetime 3600 ceph config set osd bluestore_slow_ops_warn_threshold 10