Hi, I'm evaluating performance of different targets (actually LIO and IET) on top of RAID5 (mdraid) for my customer. In this particular test (streaming write in several threads) load is provided by a windows 7 machine with robocopy and its default settings (8 threads). As expected, blockio writes are slow for both targets (~33 Mb/s), fileio with wb cache performs better. What is really weird, is that kernel version affects fileio+wb a lot, but in a different directions for targets. I have similar iscsi parameters for both targets (except 3.4's LIO misses MaxRecvDataSegmentLength), and I set Wthreads=2 for IET. What I see: IET (with fileio+wb) shows: * 75 MB/s with kernel 3.4 (from debian) * 85 MB/s with kernel 3.9 LIO (with fileio+wb) shows: * 63 MB/s with kernel 3.4 (from debian) * 54 MB/s with kernel 3.9 Is there any explanation for LIO performance degradation with the kernel upgrade? Thank you, Vladislav -- Vladislav Bogdanov Systems Architect tel.: +375 17 3091709 fax: +375 17 3091717 mob.: +375 29 6887526 E-mail: v.bogdanov@xxxxxxxxxxxxxxxxx SaM Solutions Minsk office, Belarus (GMT+3) www.sam-solutions.net Value of Talent. Delivered. -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
