>>Did your RAID setup improve anything? I have tried to launch 2 fio test in parallel, on 2 disks in the same guest vm, I get 2500iops for each test .... Running 2 fio tests, on 2 differents guests, give me 5000iops for each test. I really don't understand...Maybe something don't use parallelim from 1 kvm process ? (monitor access, or something else...) So raid don't help. >> Have you tried scaling past 4 guests in parallel? Not Yet,I'll done more tests this week ----- Mail original ----- De: "Gregory Farnum" <greg@xxxxxxxxxxx> À: "Dietmar Maurer" <dietmar@xxxxxxxxxxx> Cc: "Marcus Sorensen" <shadowsor@xxxxxxxxx>, "Josh Durgin" <josh.durgin@xxxxxxxxxxx>, "Alexandre DERUMIER" <aderumier@xxxxxxxxx>, "Sage Weil" <sage@xxxxxxxxxxx>, "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx> Envoyé: Samedi 3 Novembre 2012 18:09:11 Objet: Re: slow fio random read benchmark, need help On Thu, Nov 1, 2012 at 6:00 PM, Dietmar Maurer <dietmar@xxxxxxxxxxx> wrote: > I always thought a distributed block storage could do such things > faster (or at least as fast) than a single centralized store? That rather depends on what makes up each of them. ;) On Thu, Nov 1, 2012 at 6:11 AM, Alexandre DERUMIER <aderumier@xxxxxxxxx> wrote: > I have some customers with some huge databases (too big to be handle in the bufer), require a lot of ios. (around 10K). > > I have redone tests with 4 guest in parallel, I get 4 x 5000iops, so it seem to scale ! (and cpu is very low on the ceph cluster). > > > So I'll try some tricks, like raid over multiple rbd devices, maybe it'll help. Did your RAID setup improve anything? Have you tried scaling past 4 guests in parallel? I still haven't come up with a good model for what could be causing these symptoms. :/ -Greg -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
