Greetings, I've successfully built a Linux storage device for testing using tgt to serve logical volumes on 1.5TB of SSDs in a RAID0 over iSER with IB as the interconnect. This device was built to run and test kvm guests from. I'm testing with RAID0 here just for the speed - redundancy is not important yet. The hosts attach to the storage via iSER, and then expose these luns to their kvm guests. Already the speeds are very impressive, but I'd like to better understand how all of these layers interplay, so I can learn to better tune the system. I wrote a script to do a bunch of fio tests from a guest through to the storage device. The guest has 4 vcpus and 12GB ram and uses virtio. The tests try a bunch of block sizes and threads (1-4) to see how the different settings relate to bandwidth, iops, etc. An online copy can be seen here: http://snipurl.com/25a2m2n the script I used is here: http://snipurl.com/25a2nan if anyone is interested. I'm not really sure what to tweak at what point in the stack to maximize guest performance. Can anyone shed some light on this? I realize there are many unrelated-to-tgt layers here, but thanks for any advice you can give. Regards, Christopher -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
