bonnie++ is, as Jeff says, well-known as a canonical example of a benchmark gone horribly wrong; see Brendan Gregg's excellent post on active benchmarking and b

bonnie++ is, as Jeff says, well-known as a canonical example of a benchmark gone horribly wrong; see Brendan Gregg's excellent post on active benchmarking and bonnie++[1] for the gory details. Beyond bonnie++, storage benchmarks are fraught with peril; years ago, I dismembered SPEC SFS as being similarly unsafe at any speed when benchmarking storage systems, albeit for much more subtle reasons than the glaring mechanical flaws in bonnie++.[2] And as for dd, I actually think it's okay as long as you explain clearly what it is (and isn't); Jeff's complaint is that they seem to be treating this single dd invocation as "write performance", when it fact the truth is subtler -- and things like blocksize and synchronicity matter a great deal. More generally, anyone interested in storage benchmarks would be wise to read essentially everything that Brendan Gregg has written on the subject, starting with his five-part (!!) series on file system latency.[3][4][5][6][7] [1] http://www.brendangregg.com/ActiveBenchmarking/bonnie++.html http://www.brendangregg.com/ActiveBenchmarking/bonnie++.html [2] http://dtrace.org/blogs/bmc/2009/02/02/eulogy-for-a-benchmark/ http://dtrace.org/blogs/bmc/2009/02/02/eulogy-for-a-benchmar... [3] http://dtrace.org/blogs/brendan/2011/05/11/file-system-latency-part-1/ http://dtrace.org/blogs/brendan/2011/05/11/file-system-laten... [4] http://dtrace.org/blogs/brendan/2011/05/13/file-system-latency-part-2/ http://dtrace.org/blogs/brendan/2011/05/13/file-system-laten... [5] http://dtrace.org/blogs/brendan/2011/05/18/file-system-latency-part-3/ http://dtrace.org/blogs/brendan/2011/05/18/file-system-laten... [6] http://dtrace.org/blogs/brendan/2011/05/24/file-system-latency-part-4/ http://dtrace.org/blogs/brendan/2011/05/24/file-system-laten... [7] http://dtrace.org/blogs/brendan/2011/06/03/file-system-latency-part-5/ http://dtrace.org/blogs/brendan/2011/06/03/file-system-laten...