On Wed, 2013-10-02 at 14:07 -0500, Xianghua Xiao wrote: > after I changed default_cmdsn_depth to 64 I use iomter to do READ, > only core0 is busy, for WRITE, all cores(12 of them) are equally busy. > Have you been able to isolate the issue down to per session performance..? What happens when the same MD RAID backend is accessed across multiple sessions via a different TargetName+TargetPortalGroupTag endpoint..? Does the performance stay the same..? Also, it would be useful to confirm with a rd_mcp backend to determine if it's something related to the fabric (eg: iscsi) or something related to the backend itself. > I created 12 target(each has one LUN) for 12-cores in this case, still > the performance for both READ and WRITE are about 1/3 comparing to > SCST I got in the past. > Can you send along your rtsadmin/targetcli configuration output in order to get an idea of the setup..? Also, any other information about the backend configuration + hardware would be useful as well. Also, can you give some specifics on the workload in question..? > is LIO-iSCSI on 3.8.x 'best' for 10/100/1G network only? other than > the DEFAULT_CMDSN_DEPTH definition what else I could tune for 10G/40G > iSCSI? Again I am using the same scheduler/ fifo_batch > strip_cache_size read_ahead_kb etc parameters as I used with SCST, > the only major difference is LIO vs SCST itself. If your on IB/RoCE/iWARP verbs capable hardware, I'd very much recommend checking out the iser-target that is included in >= v3.10 kernels. --nab -- 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
