On Tue, Oct 30, 2012 at 2:38 PM, Stefan Priebe - Profihost AG <s.pri...@profihost.ag> wrote: > Am 30.10.2012 14:36, schrieb Gandalf Corvotempesta: > >> 2012/10/30 Gregory Farnum <g...@inktank.com>: >>> >>> Not a lot of people are publicly discussing their sizes on things like >>> that, unfortunately. I believe DreamHost is still the most open. They >>> have an (RGW-based) object storage service which is backed by ~800 >>> OSDs and are currently beta-testing a compute service using RBD, which >>> you can see described here: >>> http://www.youtube.com/watch?v=l_8Y988fO44&feature=plcp > > > But there's still the problem of slow random write IOP/s. At least i haven't > seen any good benchmarks.
It's not magic — I haven't done extensive testing but I believe people see aggregate IOPs of about what you can calculate: (number of storage disks * IOPS per disks) / (replication level) The journaling bumps that up a little bit for bursts, of course; similarly if you're doing it on a brand new RBD image it can be a bit slower since you need to create all the objects as well as write data to them. You need to architect your storage system to match your requirements. If you want to run write-heavy databases on RBD, there are people doing that. They're using SSDs and are very pleased with its performance. *shrug* -Greg -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
