On 2/6/13 8:10 AM, "Jens Axboe" <axboe@xxxxxxxxx> wrote: >On Mon, Feb 04 2013, Neto, Antonio Jose Rodrigues wrote: >> Hi All, >> >> This is neto from Brazil >> >> How are you? >> >> I am doing a performance POC and I need to simulate 100% true random >>workload. I am using Fibre Channel and Windows 2008R2. >> >> I have 8 LUNs (125GB each) and my configuration file is: >> >> [workload] >> bs=8k >> ioengine=windowsaio >> iodepth=3 >> numjobs=35 >> direct=1 >> runtime=120 >> size=1024g >> filename=\\.\PhysicalDrive1 >> filename=\\.\PhysicalDrive2 >> filename=\\.\PhysicalDrive3 >> filename=\\.\PhysicalDrive4 >> filename=\\.\PhysicalDrive5 >> filename=\\.\PhysicalDrive6 >> filename=\\.\PhysicalDrive7 >> filename=\\.\PhysicalDrive8 >> zonesize=1024m >> zoneskip=3g >> rw=randrw >> rwmixread=80 >> rwmixwrite=20 >> thread >> unified_rw_reporting=1 >> group_reporting=1 >> randrepeat=0 >> norandommap >> >> Questions: >> >> 1) I am assuming the working set is the size parameter that is 1TB. Is >> that correct? > >Correct > >> 2) What is the correlaction of the zonesize and zoneskip with the >> randomness? Adding those will help with the randomness of the workload >> or not? > >Your setting of zonesize=1g, skip=3g, will do random read/write within a >1gb zone (so from 0-1G initially), then move to the next zone (3G-4G), >etc. For a rotating drive, this will mean shorter seeks, since while it >is doing one zone, it will only seek within that zone. > >> 3) If I use zonesize=1024m and zoneskip=3g I have like 100K IOPS >> (coming from cache not disks) and if I use zonesize=10g and >> zoneskip=26g I have more realistic numbers. Could someone explain >> which is the a good example to use zonesize and zoneskip? > >Depends on what you want, really. With zonesize=10g, you are now seeking >in a 10x wider area than you were before. > >> 4) Is it possible with fio to specify per disk randomness area: For >> example: disk1 - start blocks 456 till blocks 3456, disk2 - start >> blocks 4567 to 103456 > >You'd have to use different jobs. You above example uses 8 disks and >accesses them from all 35 jobs. You could split it a bit, so that you >have 8 sections, each accessing one disk. You could have 4 jobs in each >section, giving you a total of 32 jobs. Then you can set offset/size for >each job separately. > >-- >Jens Axboe > >-- >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 Thank you so much my friend. Could you please do me a big favor send me an example (worse for mechanical disks (with zones, offsets, different areas etc)). I would like to make a blog post about it and we also could add it in our examples in FIO distribution. I just need the "perfect" random test for mechanical disks. I have some doubts between the relation about zones and offsets. If you could give me an example, I really appreciate. > -- 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
