On 02/09/2012 06:46 AM, Hu Tao wrote:
> >I've re-tested today, with host kernel 2.6.35.6-45.fc14.x86_64,
> >2.6.32-71.el6.x86_64, 3.1.0 and 3.3.0-rc1+, qemu version and guest
> >configuration remain the same, including guest kernel. It apears
> >that the problem appears only when the host kernel version is 3.1.0.
Sorry, forget about the kernel versions. With very heavy IO load, it's
easy to reproduce the problem. In my case, 300 disks were attached to a
virtio-scsi HBA, and 300 dd processes were launched at the same time,
each for a disk.
Yes, we're not yet optimizing for _that_ kind of scalability. :) That
raw works is already surprising enough to me!
What disk was it? Can you try on an SSD?
Paolo
