Il 14/06/2012 14:07, Stefan Hajnoczi ha scritto: > Perfect, thanks. virtio-scsi userspace is much better than virtio-blk > here. That's unexpected since they both use the QEMU block layer. If > anything, I would have expected virtio-blk to be faster!
Yes, I would have expected something similar. A blktrace would be useful here because Asias measured the opposite---virtio-scsi being much slower than virtio-blk. > The second question is why is tcm_vhost faster than virtio-scsi > userspace. I would expect a difference on more high-end benchmarks (i.e. lots of I/O to lots of disks), similar to vhost-blk. In this simple case I wonder how much it is due to the vagaries of the I/O scheduler, or even statistical noise. Paolo
