Hello, In benchmarking ceph I've been using fio / fiologparser, and want to get out the sort of stats & percentiles fiologparser currently gives (min, avg, max, percentiles). However I'm concerned the data coming out of fio is insufficient when I pass it the log_avg_msec argument. Namely using the average of a possibly asymmetric sample distribution (the set of I/O request samples over which fio is averaging when I pass it this argument) will not give accurate percentiles. Something like this argument is necessary though to keep the log files a reasonable size. Would it be a good idea to push the sort of statistics done in the log parser directly into fio? I'm considering writing some code to compute the quantiles directly in fio, either brute-force by maintaining a sorted list or implementing something like the algorithm described here: http://www.cs.rutgers.edu/~muthu/bquant.pdf with some acceptable user-defined level of error given to fio when asked to compute the percentiles on long-running / large data sets. Is there any interest in having this added directly into fio? If so where in the code should I be looking? -Karl Cronburg- -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
