On 19.11.2010, at 10:12, Stefan Hajnoczi wrote: > On Thu, Nov 18, 2010 at 11:24 PM, Alexander Graf <ag...@suse.de> wrote: >> linux-uztg:~ # dd if=/dev/sdc of=/dev/null bs=10M count=300 iflag=direct > > That's a big block size. bs=8k is interesting too because we see the > per-request overhead. Since IDE, SATA, and virtio have different > hardware interfaces that the guest drives we may see an interesting > picture with small block sizes.
IDE: 60MB/s SATA: 100MB/s virtio: 120 MB/s I had a pretty big jitter on that one though, with SATA going between 80MB and 120MB :). But overall, it's the same picture as the one with big block sizes. Alex
