Hello Dan, On Fri, 20 Dec 2013 14:01:04 +0100 Dan van der Ster wrote:
> On Fri, Dec 20, 2013 at 9:44 AM, Christian Balzer <ch...@gol.com> wrote: > > > > Hello, > > > > On Fri, 20 Dec 2013 09:20:48 +0100 Dan van der Ster wrote: > > > >> Hi, > >> Our fio tests against qemu-kvm on RBD look quite promising, details > >> here: > >> > >> https://docs.google.com/spreadsheet/ccc?key=0AoB4ekP8AM3RdGlDaHhoSV81MDhUS25EUVZxdmN6WHc&usp=drive_web#gid=0 > >> > > That data is very interesting and welcome, however it would be a lot > > more relevant if it included information about your setup (though it is > > relatively easy to create a Ceph cluster than can saturate GbE ^.^) and > > your configuration. > > > > For example I assume you're using the native QEMU RBD interface. > > How did you configure caching, just turned it on and left it at the > > default values? > > > > It's all RedHat 6.5, qemu-kvm-rhev-0.12.1.2-2.415.el6_5.3 on the HVs, > ceph 0.67.4 on the servers. Caching is enabled with the usual > rbd cache = true > rbd cache writethrough until flush = true > (otherwise defaults) That's a good data point, I'll probably play with those defaults eventually. One thinks that the same amount of cache as a consumer HD can be improved upon, given memory prices and all. ^o^ > The hardware is 47 OSD servers with 24 OSDs each, single 10GbE NIC per > server, no SSDs, write journal as a file on the OSD partition (which > is a baaad idea for small write latency, so we are slowly reinstalling > everything to put the journal on a separate partition) > Ah yes, there is the impressive bit, 47 times 24 should easily give you that amount of IOPs, even with the journal not optimized. Regards, Christian > Cheers, Dan > > >> tl;dr: rbd with caching enabled is (1) at least 2x faster than the > >> local instance storage, and (2) reaches the hypervisor's GbE network > >> limit in ~all cases except very small random writes. > >> > >> BTW, currently we have ~10 VMs running those fio tests in a loop, and > >> we're seeing ~25,000op/s sustained in the ceph logs. Not bad IMHO. > > Given the feedback I got from my "Sanity Check" mail, I'm even more > > interested in the actual setup you're using now. > > Given your workplace, I expect to be impressed. ^o^ > > > >> Cheers, Dan > >> CERN IT/DSS > >> > > [snip] > > > > Regards, > > > > Christian > > -- > > Christian Balzer Network/Systems Engineer > > ch...@gol.com Global OnLine Japan/Fusion Communications > > http://www.gol.com/ > > _______________________________________________ > > ceph-users mailing list > > ceph-users@lists.ceph.com > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- Christian Balzer Network/Systems Engineer ch...@gol.com Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
