There's nothing in the CPU graph that suggests soft lock-ups at these times. However, thank you for pointing out that the disk io scheduler could have an impact. Ubuntu seems to be on mq-deadline by default, so we just switched to none, as it fits our workload best I believe. I don't know if this will fix our issue, but I think it's worth testing. On 1/18/23 11:17, Frank Schilder wrote:
Do you have CPU soft lock-ups around these times? We had these timeouts due to using the cfq/bfq disk schedulers with SSDs. The osd_op_tp thread timeout is typical when CPU lockups happen. Could be a sporadic problem with the disk IO path.
-- Jean-Philippe Méthot Senior Openstack system administrator Administrateur système Openstack sénior PlanetHoster inc.