[ceph-users] Re: how ceph OSD bench works?

OSD bench performs IOs at the objectstore level and the stats are reported based on the response from those transactions. It performs either sequential or random IOs (i.e. a random offset into an object) based on the arguments passed to it. IIRC if number of objects and object size is provided, a random offset into an object is written.

Therefore, depending on the parameters passed, sequential or random offset is determined and this obviously would result in different measurements.

Do you know if it tries and do this on times where the osd is not being actively used or waits until there is no activity? I have been testing a bit recently and noticed that some ssd's of the same type are reporting significantly different values like 117 and 90