Hi, guys.

I want to change block I/O throttle using 'virsh blkdeviotune' with vm not running, it reported an error:

# virsh blkdeviotune instance-000000dc /dev/loop0 --total-bytes-sec 20000000 --total-iops-sec 20 --config
error: Unable to change block I/O throttle
error: unsupported configuration: block I/O throttling not supported with this QEMU binary

I can do this when the vm is running. Is it a bug? How can I fix this problem.

BTW,My libvirt version is 0.9.13:

# virsh version
Compiled against library: libvir 0.9.13
Using library: libvir 0.9.13
Using API: QEMU 0.9.13
Running hypervisor: QEMU 1.1.2

Thanks.

2012-11-28

hzguanqiang