On Wed, 30 Jan 2008 14:10:47 +0100 "Bart Van Assche" <bart.vanassche@xxxxxxxxx> wrote: > On Jan 30, 2008 11:56 AM, FUJITA Tomonori <tomof@xxxxxxx> wrote: > > On Wed, 30 Jan 2008 09:38:04 +0100 > > "Bart Van Assche" <bart.vanassche@xxxxxxxxx> wrote: > > > > > > Please specify which parameters you are referring to. As you know I > > > > Sorry, I can't say. I don't know much about iSER. But seems that Pete > > and Robin can get the better I/O performance - line speed ratiwo with > > STGT. > > Robin Humble was using a DDR InfiniBand network, while my tests were > performed with an SDR InfiniBand network. Robin's results can't be > directly compared to my results. I know that you use different hardware. I used 'ratio' word. BTW, you said the performance difference of dio READ is 38% but I think it's 27.3 %, though it's still large. > Pete Wyckoff's results > (http://www.osc.edu/~pw/papers/wyckoff-iser-snapi07-talk.pdf) are hard > to interpret. I have asked Pete which of the numbers in his test can > be compared with what I measured, but Pete did not reply. > > > The version of OpenIB might matters too. For example, Pete said that > > STGT reads loses about 100 MB/s for some transfer sizes for some > > transfer sizes due to the OpenIB version difference or other unclear > > reasons. > > > > http://article.gmane.org/gmane.linux.iscsi.tgt.devel/135 > > Pete wrote about a degradation from 600 MB/s to 500 MB/s for reads > with STGT+iSER. In my tests I measured 589 MB/s for reads (direct > I/O), which matches with the better result obtained by Pete. I don't know he used the same benchmark software so I don't think that we can compare them. All I tried to say is the OFED version might has big effect on the performance. So you might need to find the best one. > Note: the InfiniBand kernel modules I used were those from the > 2.6.22.9 kernel, not from the OFED distribution. I'm talking about a target machine (I think that Pete was also talking about OFED on his target machine). STGT uses OFED libraries, I think. - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
