On 12 September 2017 at 01:15, Blair Bethwaite <blair.bethwaite@xxxxxxxxx> wrote: > Flow-control may well just mask the real problem. Did your throughput improve? Also, does that mean flow-control is on for all ports on the switch...? IIUC, then such "global pause" flow-control will mean switchports with links to upstream network devices will also be paused if the switch is attempting to pass packets from those ports down to a congested host. Sorry, I didn't finish explaining that... The problem in the above scenario is that global-pause is link-level, so even if you have other flows destined for non-congested hosts on the same switch and plenty of upstream/fabric link capacity for them, those flows will also get paused due to a single congested downstream host. For any particular topology and congestion rate there is likely to be a tipping point. -- Cheers, ~Blairo _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com