On Mon, Feb 15 2010, Michael O'Sullivan wrote: > Hi everyone, > > I am having a problem using iolog files to generate I/O. The attached > test_fio file and spc_bsu0_str3 iolog files should run together to > generate 6 reads and 10 writes on /mnt/xphost/asu1. Fio runs via > > fio test_fio > > and generates the following output that looks good > > stream0: (groupid=0, jobs=1): err= 0: pid=19187 > read : io=24,576B, bw=18,745B/s, iops=4, runt= 1311msec > clat (usec): min=35, max=564, avg=125.17, stdev=214.99 > bw (KB/s) : min= 12, max= 31, per=119.44%, avg=21.50, stdev=13.44 > write: io=40,960B, bw=31,243B/s, iops=7, runt= 1311msec > clat (usec): min=25, max=72, avg=49.00, stdev=12.35 > bw (KB/s) : min= 25, max= 25, per=83.33%, avg=25.00, stdev= 0.00 > cpu : usr=0.00%, sys=0.31%, ctx=27, majf=0, minf=22 > IO depths : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, > >=64=0.0% > submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, > >=64=0.0% > complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, > >=64=0.0% > issued r/w: total=6/10, short=0/0 > lat (usec): 50=62.50%, 100=31.25%, 750=6.25% > > > Run status group 0 (all jobs): > READ: io=24KB, aggrb=18KB/s, minb=18KB/s, maxb=18KB/s, mint=1311msec, > maxt=1311msec > WRITE: io=40KB, aggrb=30KB/s, minb=31KB/s, maxb=31KB/s, mint=1311msec, > maxt=1311msec > > Also, if I use inotifywatch shows the correct number of access and > modify (read and write) on /mnt/xphost/asu1. However, iotop shows that > only 8KB of reads and 8KB of writes have been performed by the IO > generating process...! I have run soe other tests and fio shows much > better performance than expected because it is only generating a small > fraction of the requested IO. I have been tinkering with the fio code, > so I'm worried I broke something and would like to know what. Can anyone > help? Caching? If you uncomment the direct=1, does it do as you want? Or is it fio not actually issuing those reads and writes? -- 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
