>> Right now RBD in KVM is limited by CPU speed. Good to known, so it's seem lack of threading, or maybe somes locks. (so faster cpu give more iops).
If you lauch parallel fio on same host on different guest, do you get more total iops ? (for me it's scale) if you launch 2 parallel fio, on same guest (on differents disk), do you get more iops ? (for me, it doesn't scale, so raid0 in guest doesn't help). ----- Mail original ----- De: "Stefan Priebe" <[email protected]> À: "Alexandre DERUMIER" <[email protected]> Cc: "eric" <[email protected]>, [email protected] Envoyé: Dimanche 11 Novembre 2012 13:07:36 Objet: Re: [pve-devel] less cores more iops / speed Am 11.11.2012 12:12, schrieb Alexandre DERUMIER: > If I remember good, stefan can achieve 100.000 iops with iscsi with same kvm > host. Correct but this was always with scsi-generic and I/O multipathing on host. rbd does not support scsi-generic ;-( > I have checked ceph mailing, stefan seem to have resolved his problem with > dual core with bios update ! Correct. So speed on Dual Xeon is now 14.000 IOP/s and 18.000 IOP/s on Single Xeon. But the difference is an issue of the CPU Speed. 3,6Ghz Single Xeon vs. 2.5Ghz Dual Xeon. Right now RBD in KVM is limited by CPU speed. Greets, Stefan _______________________________________________ pve-devel mailing list [email protected] http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
