g...@inktank.com said: > > > The rados benchmark was run on one of the OSD > machines. Read and write results looked like this (the > objects size was just the default, which seems to be 4kB): > Actually, that's 4MB. ;)
Oops! My plea is that I was the victim of a man page bug: bench seconds mode [ -b objsize ] [ -t threads ] Benchmark for seconds. The mode can be write or read. The default object size is 4 KB, and the default number of simulated threads (parallel writes) is 16. > Can you run # rados bench -p pbench 900 write -t 256 > -b 4096 and see what that gets? It'll run 256 simultaneous 4KB writes. (You > can also vary the number of simultaneous writes and see if that impacts it.) Here's the new benchmark output: Total time run: 900.880070 Total writes made: 537187 Write size: 4096 Bandwidth (MB/sec): 2.329 Stddev Bandwidth: 2.57691 Max bandwidth (MB/sec): 12.6055 Min bandwidth (MB/sec): 0 Average Latency: 0.429315 Stddev Latency: 0.891734 Max latency: 19.7647 Min latency: 0.016743 > However, my suspicion is that you're limited by metadata throughput here. How > large are your files? There might be some MDS or client tunables we can > adjust, but rsync's workload is a known weak spot for CephFS. -Greg The file size is generally small. Here's the distribution: http://ayesha.phys.virginia.edu/~bryan/filesize.png The mean is about 2.5 MB. Bryan -- ======================================================================== Bryan Wright |"If you take cranberries and stew them like Physics Department | applesauce, they taste much more like prunes University of Virginia | than rhubarb does." -- Groucho Charlottesville, VA 22901| (434) 924-7218 | br...@virginia.edu ======================================================================== -- 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