>>Does "rbd op threads = N" solve bottleneck? IMHO it is possible to make this >>value automated by QEMU from num-queues. If now not. http://tracker.ceph.com/issues/15034 https://github.com/ceph/ceph/pull/8459 it's forced to 1 for now ----- Mail original ----- De: "Dzianis Kahanovich" <mahatma@xxxxxxx> À: "aderumier" <aderumier@xxxxxxxxx>, "Simon Leinen" <simon.leinen@xxxxxxxxx> Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx> Envoyé: Vendredi 9 Septembre 2016 17:20:24 Objet: Re: virtio-blk multi-queue support and RBD devices? Does "rbd op threads = N" solve bottleneck? IMHO it is possible to make this value automated by QEMU from num-queues. If now not. Alexandre DERUMIER пишет: > Hi, > > I'll test it next week to integrate it in proxmox. > > But I'm not sure I'll improve too much performance , > > until qemu will be able to use multiple iothread with multiple queue. > (I think that Paolo Bonzini still working on this currently). > > The main bottleneck with rbd currently, is cpu usage (limited to 1 iothread by disk) > > I'll send a benchmark report to the ceph mailing next week. > > > > ----- Mail original ----- > De: "Simon Leinen" <simon.leinen@xxxxxxxxx> > À: "ceph-users" <ceph-users@xxxxxxxxxxxxxx> > Envoyé: Samedi 3 Septembre 2016 19:37:50 > Objet: virtio-blk multi-queue support and RBD devices? > > One of the new features in Qemu 2.7[1] is > > * virtio-blk now supports multiqueue through a "num-queues" device > property. > > We use virtio-blk in our OpenStack cluster to expose RBD volumes to > Qemu/KVM VMs. Can RBD-backed virtio-blk benefit from multiple queues? > > (I'm hopeful because virtio-scsi had multi-queue support for a while, > and someone reported increased IOPS even with RBD devices behind those.) > -- WBR, Dzianis Kahanovich AKA Denis Kaganovich, http://mahatma.bspu.by/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |