If you create a pool with size 1 (no replication), (2) should be somewhere around 3x the speed of (1) assuming the client workload has enough parallelism and is well distributed over objects (so a random rbd workload with a large queue depth rather than a small sequential workload with a small queue depth). If you have 3x replication on (2), but 1x on (1), you should expect (2) to be pretty close to (1), perhaps a bit slower due to replication latency. The details will actually depend a lot on the workload. Do you intend to use rbd? -Sam On Fri, Aug 23, 2013 at 2:41 PM, Sushma R <gsushma@xxxxxxxxx> wrote: > Hi, > > I understand that Ceph is a scalable distributed storage architecture. > However, I'd like to understand if performance on single node cluster is > better or worse than a 3 node cluster. > Let's say I have the following 2 setups: > 1. Single node cluster with one OSD. > 2. Three node cluster with one OSD on each node. > > Would the performance of Setup 2 be approximately (3x) of Setup 1? (OR) > Would Setup 2 perform better than (3x) Setup 1, because of more parallelism? > (OR) > Would Setup 2 perform worse than (3x) Setup 1, because of replication, etc. > > In other words, I'm trying to understand do we definitely need more than > three nodes to validate the benchmark results or a single/two node should > give an idea of a larger scale? > > Thanks, > Sushma > > _______________________________________________ > 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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