Hi Anthony, Thanks for answering. >> Which SSD model and firmware are you using? Which HBA? Well, from what I can see it's basically from all our SSD's, which unfortunately varies a bit. But from the example I posted the particular disk was, SSD SATA 6.0 Gb/s /0/100/1/0/0.8.0 /dev/sdg disk 800GB INTEL SSDSC2BX80 PERC H730P Mini (25.5.3.0005) All our SSD's are configured as pass through so I wouldn't think that the controller would be involved to much. >> Compaction may well be a factor as well, but I’ve experienced hardware/firmware issues as well so I had to ask. Well, my guess is that it is the compaction, and that there may be ways of tuning this. I'm just curious about "how to do it", and if those "spikes" we see are "normal operation and nothing to worry about", or if one actually should take some sort of action. Thanks for answering! Best Regards, Patrik Martinsson, Sweden _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com