On Sun, May 8, 2011 at 7:43 PM, Simon Tian <[email protected]> wrote: > Hi folks, > > I am testing the replication performance of ceph-0.26 with > libceph, write 1G data in with ceph_write() and read it out with > ceph_read(), > > rep_size 1 2 > 3 4 > write： 78.8 MB/s 39.38 MB/s 27.7 MB/s > 20.90 MB/s > read： 85.3 MB/s 85.33 MB/s 78.77MB/s > 78.77MB/s > > I think if the replication strategy is splay or primary copy, not the > chain, as the thesis said, writing speed for 3, 4 or even more > replication will be a little worse than 2 replication, should be near > with 39.38 MB/s. > But the write performance I got is affect so much by size of replication. > > What is the replication strategy in ceph-0.26, not splay? If splay, > why not near with 39.38 MB/s? > > There is 5 OSDs in 2 hosts, 2 in one and 3 int the other.
The replication strategy has been fixed at primary copy for several years now. At expected replication levels (2-3) there just isn't a big difference between the strategies, and limiting it to primary-copy replication makes a lot of the bookkeeping for data safety much easier to handle. -Greg -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
