Sylar: Did you run this using Ceph's FUSE or in-kernel client? If this is on cfuse, the results don't surprise me -- it's not very well optimized! If this is using the kernel client, I'd expect much faster results on the buffered write test -- I think speeds approaching the network interface limits are more typical. What level of replication are you using, and what does your network look like? Is it possible that a switch or router is limiting your total throughput? On the dsync run, those results look about right -- you could probably get higher bandwidths by using a larger block size but synchronous IO is just slow over all network filesystems. On a different note, you might want to try with a larger test set -- 100,000 8KB blocks is only 781MB, which should fit in RAM with room to spare. :) -Greg On Wednesday, March 9, 2011 at 5:32 PM, Sylar Shen wrote: Hi, > I know that Ceph can re-export nfs protocol. > So I want to compare the speed differences between Ceph and Gluster. > I use Linux command "dd" to make a write test. Here is the command I used. > "dd if=/dev/zero of=/mnt/test1.dbf bs=8k count=100000" > The hardware conditions are the same. > I set Gluster as 20 servers and Ceph as 1 MDS, 19 OSDes and 1 MON(MDS > and Mon are on the same server). > I have one physical server as a client. > The results are as follows: > 1. with oflag=dsync > Gluster=166KB/s > Ceph=174KB/s > 2. without oflag=dsync > Gluster=39.3MB/s > Ceph=46.6MB/s > > This confuses me. Because I thought Ceph should be a lot faster than Gluster. > But it seems not according the results. > Could someone tell me if I did something wrong or the result is OK? > Thanks in advance! > -- > Best Regards, > Sylar Shen > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
