Hi Jens & Group, I've got an interesting one here and am wondering if there is a better way to run this. I'm trying to run a particular benchmark for HDD's and need to run large sequential writes (1M) and intersperse it with small random reads (4K). I don't think I can run this within a single job, as even though I could specify read/write mix (rwmixread) and specify sequential/random mix (percentage_random), I am unable to guarantee that the reads are in fact random. So this is my jobfile (fio 2.1); [global] direct=1 ioengine=libaio filename=/dev/sdb runtime=30s [Writes] rw=write bs=1M iodepth=3 flow=-1 [Reads] rw=randread bs=4K iodepth=2 flow=30 As you can see I'm using the flow= argument, and I think it is working correctly, rough ratio of 1:30, or 3 percent reads. One thing that I can't see and it would be good (and a way to prove the randomness of the random reads) is a log file that contains both writes and reads in the order they are processed. I can use the write_iolog= argument, but if I place it in global it seems to record all the writes close and reopen the file and then the reads so I am unable to match up the actual sequence of writes/reads, is there an argument that will do this that I'm missing? Has anybody done anything similar to this to see the impact on large sequential writes? Or see a better way to run this? Thanks, Gavin -- ------------------------------ For additional information including the registered office and the treatment of Xyratex confidential information please visit www.xyratex.com ------------------------------ -- 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
