Re: [libvirt-users] error: unsupported configuration: block I/O throttling not supported with this QEMU binary

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 >process. > >Osier 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.