Three things come to my mind when looking at your setup/results: 1)The number of pg's. According to the documentation it should be:
(number of OSD * 100 ) / number of replicas. Maybe playing with the number a bit would yield better results. 2) Although I am NOT using SSD's as journals, I am using 10GigE with 6 nodes and 72 OSD's, and I am able to get around 1100 MB/s using rados bench and the default 4 MB object size, the default number of threads (16) and 1 replica. It seems like the consensus is that you should front around 4 to 6 OSD's total per SSD in order to get the best performance. Also you need to make sure that the SSD's that you are using can actually handle the combined write throughput from 10 OSD's. Otherwise the SSD's become the bottleneck. 3) What is the output if you just use the default number of threads (instead of 100)? For example: 'rados bench -p test3 30 write' Shain Shain Miley | Manager of Systems and Infrastructure, Digital Media | [email protected] | 202.513.3649 ________________________________________ From: [email protected] [[email protected]] on behalf of Kuo Hugo [[email protected]] Sent: Thursday, December 19, 2013 7:17 AM To: [email protected] Subject: [ceph-users] [Rados Bench Result] Maximum bandwidth only 380MB/sec with 10Gb Network. Hi folks, I'm doing a test for Rados bench now. The cluster is deployed by ceph-deploy Ceph version: Emperor FS : XFS I created a pool test3 with size1 : pool 13 'test3' rep size 1 min_size 1 crush_ruleset 0 object_hash rjenkins pg_num 2000 pgp_num 2000 last_change 166 owner 0 The Rados bench command issued from an independent benchmark machine. Public network : 10GbE Cluster network : 10GbE Result : rados bench -p test3 30 write -t 100 Total time run: 30.275789 Total writes made: 2876 Write size: 4194304 Bandwidth (MB/sec): 379.974 Stddev Bandwidth: 90.2077 Max bandwidth (MB/sec): 420 Min bandwidth (MB/sec): 0 Average Latency: 1.03858 Stddev Latency: 0.112756 Max latency: 2.20545 Min latency: 0.10155 Why the bandwidth only 379MB/sec? I expected the speed suppose to be over 900MB/sec due to the pool size only 1. There're 3 storage nodes here. 10 OSDs on each storage node + journals on a SSD with 10 partitions. Any suggestions? Thanks _______________________________________________ ceph-users mailing list [email protected] http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
