Let me know if I can help out with testing somehow. Wolfgang ________________________________________ Von: ceph-users-bounces@xxxxxxxxxxxxxx [ceph-users-bounces@xxxxxxxxxxxxxx]" im Auftrag von "Mark Nelson [mark.nelson@xxxxxxxxxxx] Gesendet: Samstag, 09. März 2013 20:33 Bis: ceph-users@xxxxxxxxxxxxxx Betreff: Re: I/O Speed Comparisons Thanks for all of this feedback guys! It gives us some good data to try to replicate on our end. Hopefully I'll have some time next week to take a look. Thanks! Mark On 03/09/2013 08:14 AM, Erdem Agaoglu wrote: > Mark, > > If it's any help, we've done a small totally unreliable benchmark on our > end. For a KVM instance, we had: > 260MB/s write, 200MB/s read on local SAS disks, attached as LVM LVs, > 250MB/s write, 90MB/s read on RBD, 32 osds, all SATA. > > All sequential, a 10G network. It's more than enough currently but we'd > like to improve RBD read performance. > > Cheers, > > > On Sat, Mar 9, 2013 at 7:27 AM, Andrew Thrift <andrew@xxxxxxxxxxxxxxxxx > <mailto:andrew@xxxxxxxxxxxxxxxxx>> wrote: > > Mark, > > > I would just like to add, we too are seeing the same behavior with > QEMU/KVM/RBD. Maybe it is a common symptom of high IO with this setup. > > > > Regards, > > > > > > Andrew > > > On 3/8/2013 12:46 AM, Mark Nelson wrote: > > On 03/07/2013 05:10 AM, Wolfgang Hennerbichler wrote: > > > > On 03/06/2013 02:31 PM, Mark Nelson wrote: > t > > If you are doing sequential reads, you may benefit by > increasing the > read_ahead_kb value for each device in > /sys/block/<device>/queue on the > OSD hosts. > > > Thanks, that didn't really help. It seems the VM has to > handle too much > I/O, even the mouse-cursor is jerking over the screen when > connecting > via vnc. I guess this is the wrong list, but it has somehow > to do with > librbd in connection with kvm, as the same machine on LVM > works just ok. > > > Thanks for the heads up Wolfgang. I'm going to be looking into > QEMU/KVM > RBD performance in the coming weeks so I'll try to watch out for > this > behaviour. > > > Wolfgang > _________________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx <mailto:ceph-users@xxxxxxxxxxxxxx> > http://lists.ceph.com/__listinfo.cgi/ceph-users-ceph.__com > <http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com> > > > > _________________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx <mailto:ceph-users@xxxxxxxxxxxxxx> > http://lists.ceph.com/__listinfo.cgi/ceph-users-ceph.__com > <http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com> > > > > > -- > erdem agaoglu > > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Mark Nelson Performance Engineer Inktank _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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