On 2012-12-03 10:33, Osier wrote:
>On 2012年11月28日 16:34, hzguanqiang wrote:
>> 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.
>It just looks strange, as you can tune when the VM is active. Because
>the qemu capabilities is collected during the qemu driver starts up,
>which is independant with the domain states.
>Probably you will want to debug the qemu capabilities collecting
Osier, Firstly, thanks for your reply.
The situation is that I want to resize the disk and meanwhile reset the block I/O throttle. And during the whole process, The vm is stopped.
I've found this was directly caused by the patch "qemu: reject blockiotune if qemu too old" post by Eric Blake long before. I've sent an email to ask him the reason. Maybe, People think you can't set I/O throtting if vm not started, I guess.
Thanks again for you guys replying.